Change license to Apache2

All contributors have agreed on public record at

    https://github.com/DanielG/cabal-helper/issues/76

Fixes #76

19 files changed, 108 insertions, 203 deletions

diff --git a/src/CabalHelper/Compiletime/Cabal.hs b/src/CabalHelper/Compiletime/Cabal.hs
index d39761d..b565152 100644
--- a/src/CabalHelper/Compiletime/Cabal.hs
+++ b/src/CabalHelper/Compiletime/Cabal.hs
@@ -1,23 +1,18 @@
 -- cabal-helper: Simple interface to Cabal's configuration state
 -- Copyright (C) 2018  Daniel Gröber <cabal-helper@dxld.at>
 --
--- This program is free software: you can redistribute it and/or modify
--- it under the terms of the GNU General Public License as published by
--- the Free Software Foundation, either version 3 of the License, or
--- (at your option) any later version.
+-- SPDX-License-Identifier: Apache-2.0
 --
--- This program is distributed in the hope that it will be useful,
--- but WITHOUT ANY WARRANTY; without even the implied warranty of
--- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
--- GNU General Public License for more details.
+-- Licensed under the Apache License, Version 2.0 (the "License");
+-- you may not use this file except in compliance with the License.
+-- You may obtain a copy of the License at
 --
--- You should have received a copy of the GNU General Public License
--- along with this program.  If not, see <http://www.gnu.org/licenses/>.
+--     http://www.apache.org/licenses/LICENSE-2.0
 
 {-|
 Module      : CabalHelper.Compiletime.Program.Cabal
 Description : Cabal library source unpacking
-License     : GPL-3
+License     : Apache-2.0
 -}
 
 {-# LANGUAGE DeriveFunctor, ViewPatterns, OverloadedStrings, CPP #-}
diff --git a/src/CabalHelper/Compiletime/Compat/Environment.hs b/src/CabalHelper/Compiletime/Compat/Environment.hs
index 58bb9ee..b40f2d8 100644
--- a/src/CabalHelper/Compiletime/Compat/Environment.hs
+++ b/src/CabalHelper/Compiletime/Compat/Environment.hs
@@ -1,18 +1,13 @@
 -- cabal-helper: Simple interface to Cabal's configuration state
 -- Copyright (C) 2017  Daniel Gröber <cabal-helper@dxld.at>
 --
--- This program is free software: you can redistribute it and/or modify
--- it under the terms of the GNU General Public License as published by
--- the Free Software Foundation, either version 3 of the License, or
--- (at your option) any later version.
+-- SPDX-License-Identifier: Apache-2.0
 --
--- This program is distributed in the hope that it will be useful,
--- but WITHOUT ANY WARRANTY; without even the implied warranty of
--- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
--- GNU General Public License for more details.
+-- Licensed under the Apache License, Version 2.0 (the "License");
+-- you may not use this file except in compliance with the License.
+-- You may obtain a copy of the License at
 --
--- You should have received a copy of the GNU General Public License
--- along with this program.  If not, see <http://www.gnu.org/licenses/>.
+--     http://www.apache.org/licenses/LICENSE-2.0
 
 {-# LANGUAGE CPP #-}
 module CabalHelper.Compiletime.Compat.Environment where
diff --git a/src/CabalHelper/Compiletime/Compat/Parsec.hs b/src/CabalHelper/Compiletime/Compat/Parsec.hs
index da316ad..cea0a2e 100644
--- a/src/CabalHelper/Compiletime/Compat/Parsec.hs
+++ b/src/CabalHelper/Compiletime/Compat/Parsec.hs
@@ -1,18 +1,13 @@
 -- cabal-helper: Simple interface to Cabal's configuration state
 -- Copyright (C) 2018  Daniel Gröber <cabal-helper@dxld.at>
 --
--- This program is free software: you can redistribute it and/or modify
--- it under the terms of the GNU General Public License as published by
--- the Free Software Foundation, either version 3 of the License, or
--- (at your option) any later version.
+-- SPDX-License-Identifier: Apache-2.0
 --
--- This program is distributed in the hope that it will be useful,
--- but WITHOUT ANY WARRANTY; without even the implied warranty of
--- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
--- GNU General Public License for more details.
+-- Licensed under the Apache License, Version 2.0 (the "License");
+-- you may not use this file except in compliance with the License.
+-- You may obtain a copy of the License at
 --
--- You should have received a copy of the GNU General Public License
--- along with this program.  If not, see <http://www.gnu.org/licenses/>.
+--     http://www.apache.org/licenses/LICENSE-2.0
 
 {-# LANGUAGE CPP #-}
 module CabalHelper.Compiletime.Compat.Parsec
diff --git a/src/CabalHelper/Compiletime/Compat/Version.hs b/src/CabalHelper/Compiletime/Compat/Version.hs
index 5d4f5f5..2feb7a1 100644
--- a/src/CabalHelper/Compiletime/Compat/Version.hs
+++ b/src/CabalHelper/Compiletime/Compat/Version.hs
@@ -1,18 +1,13 @@
 -- cabal-helper: Simple interface to Cabal's configuration state
 -- Copyright (C) 2017-2018  Daniel Gröber <cabal-helper@dxld.at>
 --
--- This program is free software: you can redistribute it and/or modify
--- it under the terms of the GNU General Public License as published by
--- the Free Software Foundation, either version 3 of the License, or
--- (at your option) any later version.
+-- SPDX-License-Identifier: Apache-2.0
 --
--- This program is distributed in the hope that it will be useful,
--- but WITHOUT ANY WARRANTY; without even the implied warranty of
--- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
--- GNU General Public License for more details.
+-- Licensed under the Apache License, Version 2.0 (the "License");
+-- you may not use this file except in compliance with the License.
+-- You may obtain a copy of the License at
 --
--- You should have received a copy of the GNU General Public License
--- along with this program.  If not, see <http://www.gnu.org/licenses/>.
+--     http://www.apache.org/licenses/LICENSE-2.0
 
 {-# LANGUAGE CPP #-}
 module CabalHelper.Compiletime.Compat.Version
diff --git a/src/CabalHelper/Compiletime/Compile.hs b/src/CabalHelper/Compiletime/Compile.hs
index 1cecb15..d2886e8 100644
--- a/src/CabalHelper/Compiletime/Compile.hs
+++ b/src/CabalHelper/Compiletime/Compile.hs
@@ -1,25 +1,20 @@
 -- cabal-helper: Simple interface to Cabal's configuration state
 -- Copyright (C) 2015-2018  Daniel Gröber <cabal-helper@dxld.at>
 --
--- This program is free software: you can redistribute it and/or modify
--- it under the terms of the GNU General Public License as published by
--- the Free Software Foundation, either version 3 of the License, or
--- (at your option) any later version.
+-- SPDX-License-Identifier: Apache-2.0
 --
--- This program is distributed in the hope that it will be useful,
--- but WITHOUT ANY WARRANTY; without even the implied warranty of
--- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
--- GNU General Public License for more details.
+-- Licensed under the Apache License, Version 2.0 (the "License");
+-- you may not use this file except in compliance with the License.
+-- You may obtain a copy of the License at
 --
--- You should have received a copy of the GNU General Public License
--- along with this program.  If not, see <http://www.gnu.org/licenses/>.
+--     http://www.apache.org/licenses/LICENSE-2.0
 
 {-# LANGUAGE DeriveFunctor, GADTs, ScopedTypeVariables #-}
 
 {-|
 Module      : CabalHelper.Compiletime.Compile
 Description : Runtime compilation machinery
-License     : GPL-3
+License     : Apache-2.0
 -}
 
 module CabalHelper.Compiletime.Compile where
diff --git a/src/CabalHelper/Compiletime/Data.hs b/src/CabalHelper/Compiletime/Data.hs
index 14793c5..3533aa7 100644
--- a/src/CabalHelper/Compiletime/Data.hs
+++ b/src/CabalHelper/Compiletime/Data.hs
@@ -1,18 +1,13 @@
 -- cabal-helper: Simple interface to Cabal's configuration state
 -- Copyright (C) 2015-2017  Daniel Gröber <cabal-helper@dxld.at>
 --
--- This program is free software: you can redistribute it and/or modify
--- it under the terms of the GNU General Public License as published by
--- the Free Software Foundation, either version 3 of the License, or
--- (at your option) any later version.
+-- SPDX-License-Identifier: Apache-2.0
 --
--- This program is distributed in the hope that it will be useful,
--- but WITHOUT ANY WARRANTY; without even the implied warranty of
--- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
--- GNU General Public License for more details.
+-- Licensed under the Apache License, Version 2.0 (the "License");
+-- you may not use this file except in compliance with the License.
+-- You may obtain a copy of the License at
 --
--- You should have received a copy of the GNU General Public License
--- along with this program.  If not, see <http://www.gnu.org/licenses/>.
+--     http://www.apache.org/licenses/LICENSE-2.0
 
 {-# LANGUAGE TemplateHaskell, ScopedTypeVariables #-}
 {-# OPTIONS_GHC -fforce-recomp #-}
@@ -20,7 +15,7 @@
 {-|
 Module      : CabalHelper.Compiletime.Data
 Description : Embeds source code for runtime component using TH
-License     : GPL-3
+License     : Apache-2.0
 -}
 
 module CabalHelper.Compiletime.Data where
diff --git a/src/CabalHelper/Compiletime/Log.hs b/src/CabalHelper/Compiletime/Log.hs
index d817098..6e2f20f 100644
--- a/src/CabalHelper/Compiletime/Log.hs
+++ b/src/CabalHelper/Compiletime/Log.hs
@@ -1,23 +1,18 @@
 -- cabal-helper: Simple interface to Cabal's configuration state
 -- Copyright (C) 2018  Daniel Gröber <cabal-helper@dxld.at>
 --
--- This program is free software: you can redistribute it and/or modify
--- it under the terms of the GNU General Public License as published by
--- the Free Software Foundation, either version 3 of the License, or
--- (at your option) any later version.
+-- SPDX-License-Identifier: Apache-2.0
 --
--- This program is distributed in the hope that it will be useful,
--- but WITHOUT ANY WARRANTY; without even the implied warranty of
--- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
--- GNU General Public License for more details.
+-- Licensed under the Apache License, Version 2.0 (the "License");
+-- you may not use this file except in compliance with the License.
+-- You may obtain a copy of the License at
 --
--- You should have received a copy of the GNU General Public License
--- along with this program.  If not, see <http://www.gnu.org/licenses/>.
+--     http://www.apache.org/licenses/LICENSE-2.0
 
 {-|
 Module      : CabalHelper.Compiletime.Log
 Description : Logging utilities
-License     : GPL-3
+License     : Apache-2.0
 -}
 
 module CabalHelper.Compiletime.Log where
diff --git a/src/CabalHelper/Compiletime/Process.hs b/src/CabalHelper/Compiletime/Process.hs
index 34404ab..9d6604e 100644
--- a/src/CabalHelper/Compiletime/Process.hs
+++ b/src/CabalHelper/Compiletime/Process.hs
@@ -1,23 +1,18 @@
 -- cabal-helper: Simple interface to Cabal's configuration state
 -- Copyright (C) 2018  Daniel Gröber <cabal-helper@dxld.at>
 --
--- This program is free software: you can redistribute it and/or modify
--- it under the terms of the GNU General Public License as published by
--- the Free Software Foundation, either version 3 of the License, or
--- (at your option) any later version.
+-- SPDX-License-Identifier: Apache-2.0
 --
--- This program is distributed in the hope that it will be useful,
--- but WITHOUT ANY WARRANTY; without even the implied warranty of
--- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
--- GNU General Public License for more details.
+-- Licensed under the Apache License, Version 2.0 (the "License");
+-- you may not use this file except in compliance with the License.
+-- You may obtain a copy of the License at
 --
--- You should have received a copy of the GNU General Public License
--- along with this program.  If not, see <http://www.gnu.org/licenses/>.
+--     http://www.apache.org/licenses/LICENSE-2.0
 
 {-|
 Module      : CabalHelper.Compiletime.Process
 Description : System process utilities
-License     : GPL-3
+License     : Apache-2.0
 -}
 
 module CabalHelper.Compiletime.Process
diff --git a/src/CabalHelper/Compiletime/Program/CabalInstall.hs b/src/CabalHelper/Compiletime/Program/CabalInstall.hs
index 67f33bd..ac7dfa6 100644
--- a/src/CabalHelper/Compiletime/Program/CabalInstall.hs
+++ b/src/CabalHelper/Compiletime/Program/CabalInstall.hs
@@ -3,23 +3,18 @@
 -- cabal-helper: Simple interface to Cabal's configuration state
 -- Copyright (C) 2018  Daniel Gröber <cabal-helper@dxld.at>
 --
--- This program is free software: you can redistribute it and/or modify
--- it under the terms of the GNU General Public License as published by
--- the Free Software Foundation, either version 3 of the License, or
--- (at your option) any later version.
+-- SPDX-License-Identifier: Apache-2.0
 --
--- This program is distributed in the hope that it will be useful,
--- but WITHOUT ANY WARRANTY; without even the implied warranty of
--- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
--- GNU General Public License for more details.
+-- Licensed under the Apache License, Version 2.0 (the "License");
+-- you may not use this file except in compliance with the License.
+-- You may obtain a copy of the License at
 --
--- You should have received a copy of the GNU General Public License
--- along with this program.  If not, see <http://www.gnu.org/licenses/>.
+--     http://www.apache.org/licenses/LICENSE-2.0
 
 {-|
 Module      : CabalHelper.Compiletime.Program.Cabal
 Description : cabal-install program interface
-License     : GPL-3
+License     : Apache-2.0
 -}
 
 module CabalHelper.Compiletime.Program.CabalInstall where
diff --git a/src/CabalHelper/Compiletime/Program/GHC.hs b/src/CabalHelper/Compiletime/Program/GHC.hs
index 4486d47..293d0af 100644
--- a/src/CabalHelper/Compiletime/Program/GHC.hs
+++ b/src/CabalHelper/Compiletime/Program/GHC.hs
@@ -1,23 +1,18 @@
 -- cabal-helper: Simple interface to Cabal's configuration state
 -- Copyright (C) 2018  Daniel Gröber <cabal-helper@dxld.at>
 --
--- This program is free software: you can redistribute it and/or modify
--- it under the terms of the GNU General Public License as published by
--- the Free Software Foundation, either version 3 of the License, or
--- (at your option) any later version.
+-- SPDX-License-Identifier: Apache-2.0
 --
--- This program is distributed in the hope that it will be useful,
--- but WITHOUT ANY WARRANTY; without even the implied warranty of
--- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
--- GNU General Public License for more details.
+-- Licensed under the Apache License, Version 2.0 (the "License");
+-- you may not use this file except in compliance with the License.
+-- You may obtain a copy of the License at
 --
--- You should have received a copy of the GNU General Public License
--- along with this program.  If not, see <http://www.gnu.org/licenses/>.
+--     http://www.apache.org/licenses/LICENSE-2.0
 
 {-|
 Module      : CabalHelper.Compiletime.Program.GHC
 Description : GHC program interface
-License     : GPL-3
+License     : Apache-2.0
 -}
 
 module CabalHelper.Compiletime.Program.GHC where
diff --git a/src/CabalHelper/Compiletime/Program/Stack.hs b/src/CabalHelper/Compiletime/Program/Stack.hs
index 075f46c..d057d65 100644
--- a/src/CabalHelper/Compiletime/Program/Stack.hs
+++ b/src/CabalHelper/Compiletime/Program/Stack.hs
@@ -1,23 +1,18 @@
 -- cabal-helper: Simple interface to Cabal's configuration state
 -- Copyright (C) 2018  Daniel Gröber <cabal-helper@dxld.at>
 --
--- This program is free software: you can redistribute it and/or modify
--- it under the terms of the GNU General Public License as published by
--- the Free Software Foundation, either version 3 of the License, or
--- (at your option) any later version.
+-- SPDX-License-Identifier: Apache-2.0
 --
--- This program is distributed in the hope that it will be useful,
--- but WITHOUT ANY WARRANTY; without even the implied warranty of
--- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
--- GNU General Public License for more details.
+-- Licensed under the Apache License, Version 2.0 (the "License");
+-- you may not use this file except in compliance with the License.
+-- You may obtain a copy of the License at
 --
--- You should have received a copy of the GNU General Public License
--- along with this program.  If not, see <http://www.gnu.org/licenses/>.
+--     http://www.apache.org/licenses/LICENSE-2.0
 
 {-|
 Module      : CabalHelper.Compiletime.Program.Stack
 Description : Stack program interface
-License     : GPL-3
+License     : Apache-2.0
 -}
 
 {-# LANGUAGE GADTs, DataKinds #-}
diff --git a/src/CabalHelper/Compiletime/Sandbox.hs b/src/CabalHelper/Compiletime/Sandbox.hs
index 6ef8693..924393a 100644
--- a/src/CabalHelper/Compiletime/Sandbox.hs
+++ b/src/CabalHelper/Compiletime/Sandbox.hs
@@ -1,23 +1,18 @@
 -- cabal-helper: Simple interface to Cabal's configuration state
 -- Copyright (C) 2015-2017  Daniel Gröber <cabal-helper@dxld.at>
 --
--- This program is free software: you can redistribute it and/or modify
--- it under the terms of the GNU General Public License as published by
--- the Free Software Foundation, either version 3 of the License, or
--- (at your option) any later version.
+-- SPDX-License-Identifier: Apache-2.0
 --
--- This program is distributed in the hope that it will be useful,
--- but WITHOUT ANY WARRANTY; without even the implied warranty of
--- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
--- GNU General Public License for more details.
+-- Licensed under the Apache License, Version 2.0 (the "License");
+-- you may not use this file except in compliance with the License.
+-- You may obtain a copy of the License at
 --
--- You should have received a copy of the GNU General Public License
--- along with this program.  If not, see <http://www.gnu.org/licenses/>.
+--     http://www.apache.org/licenses/LICENSE-2.0
 
 {-|
 Module      : CabalHelper.Shared.Sandbox
 Description : Extracting information from @cabal.sandbox.config@ files
-License     : GPL-3
+License     : Apache-2.0
 -}
 
 module CabalHelper.Compiletime.Sandbox where
diff --git a/src/CabalHelper/Compiletime/Types.hs b/src/CabalHelper/Compiletime/Types.hs
index 94e5c8e..99766dd 100644
--- a/src/CabalHelper/Compiletime/Types.hs
+++ b/src/CabalHelper/Compiletime/Types.hs
@@ -1,18 +1,13 @@
 -- cabal-helper: Simple interface to Cabal's configuration state
 -- Copyright (C) 2015-2018  Daniel Gröber <cabal-helper@dxld.at>
 --
--- This program is free software: you can redistribute it and/or modify
--- it under the terms of the GNU General Public License as published by
--- the Free Software Foundation, either version 3 of the License, or
--- (at your option) any later version.
+-- SPDX-License-Identifier: Apache-2.0
 --
--- This program is distributed in the hope that it will be useful,
--- but WITHOUT ANY WARRANTY; without even the implied warranty of
--- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
--- GNU General Public License for more details.
+-- Licensed under the Apache License, Version 2.0 (the "License");
+-- you may not use this file except in compliance with the License.
+-- You may obtain a copy of the License at
 --
--- You should have received a copy of the GNU General Public License
--- along with this program.  If not, see <http://www.gnu.org/licenses/>.
+--     http://www.apache.org/licenses/LICENSE-2.0
 
 {-# LANGUAGE DeriveGeneric, DeriveDataTypeable, DefaultSignatures,
   StandaloneDeriving, GADTs, DataKinds, KindSignatures, RankNTypes, PolyKinds #-}
@@ -20,7 +15,7 @@
 {-|
 Module      : CabalHelper.Compiletime.Types
 Description : Types used throughout
-License     : GPL-3
+License     : Apache-2.0
 -}
 
 module CabalHelper.Compiletime.Types where
diff --git a/src/CabalHelper/Compiletime/Types/RelativePath.hs b/src/CabalHelper/Compiletime/Types/RelativePath.hs
index ac26de2..15496cf 100644
--- a/src/CabalHelper/Compiletime/Types/RelativePath.hs
+++ b/src/CabalHelper/Compiletime/Types/RelativePath.hs
@@ -1,22 +1,17 @@
 -- cabal-helper: Simple interface to Cabal's configuration state
 -- Copyright (C) 2018  Daniel Gröber <cabal-helper@dxld.at>
 --
--- This program is free software: you can redistribute it and/or modify
--- it under the terms of the GNU General Public License as published by
--- the Free Software Foundation, either version 3 of the License, or
--- (at your option) any later version.
+-- SPDX-License-Identifier: Apache-2.0
 --
--- This program is distributed in the hope that it will be useful,
--- but WITHOUT ANY WARRANTY; without even the implied warranty of
--- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
--- GNU General Public License for more details.
+-- Licensed under the Apache License, Version 2.0 (the "License");
+-- you may not use this file except in compliance with the License.
+-- You may obtain a copy of the License at
 --
--- You should have received a copy of the GNU General Public License
--- along with this program.  If not, see <http://www.gnu.org/licenses/>.
+--     http://www.apache.org/licenses/LICENSE-2.0
 
 {-|
 Module      : CabalHelper.Compiletime.Types.RelativePath
-License     : GPL-3
+License     : Apache-2.0
 -}
 
 module CabalHelper.Compiletime.Types.RelativePath
diff --git a/src/CabalHelper/Runtime/Compat.hs b/src/CabalHelper/Runtime/Compat.hs
index d3fe5e6..3582766 100644
--- a/src/CabalHelper/Runtime/Compat.hs
+++ b/src/CabalHelper/Runtime/Compat.hs
@@ -1,18 +1,13 @@
 -- cabal-helper: Simple interface to Cabal's configuration state
 -- Copyright (C) 2015-2018  Daniel Gröber <cabal-helper@dxld.at>
 --
--- This program is free software: you can redistribute it and/or modify
--- it under the terms of the GNU General Public License as published by
--- the Free Software Foundation, either version 3 of the License, or
--- (at your option) any later version.
+-- SPDX-License-Identifier: Apache-2.0
 --
--- This program is distributed in the hope that it will be useful,
--- but WITHOUT ANY WARRANTY; without even the implied warranty of
--- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
--- GNU General Public License for more details.
+-- Licensed under the Apache License, Version 2.0 (the "License");
+-- you may not use this file except in compliance with the License.
+-- You may obtain a copy of the License at
 --
--- You should have received a copy of the GNU General Public License
--- along with this program.  If not, see <http://www.gnu.org/licenses/>.
+--     http://www.apache.org/licenses/LICENSE-2.0
 
 {-# LANGUAGE CPP, BangPatterns, RecordWildCards, RankNTypes, ViewPatterns,
   TupleSections #-}
diff --git a/src/CabalHelper/Runtime/HelperMain.hs b/src/CabalHelper/Runtime/HelperMain.hs
index 08cb9c5..9c4d557 100644
--- a/src/CabalHelper/Runtime/HelperMain.hs
+++ b/src/CabalHelper/Runtime/HelperMain.hs
@@ -1,18 +1,13 @@
 -- cabal-helper: Simple interface to Cabal's configuration state
 -- Copyright (C) 2015-2018  Daniel Gröber <cabal-helper@dxld.at>
 --
--- This program is free software: you can redistribute it and/or modify
--- it under the terms of the GNU General Public License as published by
--- the Free Software Foundation, either version 3 of the License, or
--- (at your option) any later version.
+-- SPDX-License-Identifier: Apache-2.0
 --
--- This program is distributed in the hope that it will be useful,
--- but WITHOUT ANY WARRANTY; without even the implied warranty of
--- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
--- GNU General Public License for more details.
+-- Licensed under the Apache License, Version 2.0 (the "License");
+-- you may not use this file except in compliance with the License.
+-- You may obtain a copy of the License at
 --
--- You should have received a copy of the GNU General Public License
--- along with this program.  If not, see <http://www.gnu.org/licenses/>.
+--     http://www.apache.org/licenses/LICENSE-2.0
 
 {-# LANGUAGE CPP, BangPatterns, RecordWildCards, RankNTypes, ViewPatterns,
   TupleSections #-}
diff --git a/src/CabalHelper/Runtime/Main.hs b/src/CabalHelper/Runtime/Main.hs
index 71dfd9b..2a13c84 100644
--- a/src/CabalHelper/Runtime/Main.hs
+++ b/src/CabalHelper/Runtime/Main.hs
@@ -1,18 +1,13 @@
 -- cabal-helper: Simple interface to Cabal's configuration state
 -- Copyright (C) 2018  Daniel Gröber <cabal-helper@dxld.at>
 --
--- This program is free software: you can redistribute it and/or modify
--- it under the terms of the GNU General Public License as published by
--- the Free Software Foundation, either version 3 of the License, or
--- (at your option) any later version.
+-- SPDX-License-Identifier: Apache-2.0
 --
--- This program is distributed in the hope that it will be useful,
--- but WITHOUT ANY WARRANTY; without even the implied warranty of
--- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
--- GNU General Public License for more details.
+-- Licensed under the Apache License, Version 2.0 (the "License");
+-- you may not use this file except in compliance with the License.
+-- You may obtain a copy of the License at
 --
--- You should have received a copy of the GNU General Public License
--- along with this program.  If not, see <http://www.gnu.org/licenses/>.
+--     http://www.apache.org/licenses/LICENSE-2.0
 
 import CabalHelper.Runtime.HelperMain (helper_main)
 import System.Environment
diff --git a/src/CabalHelper/Shared/Common.hs b/src/CabalHelper/Shared/Common.hs
index 031adcf..d95fe9b 100644
--- a/src/CabalHelper/Shared/Common.hs
+++ b/src/CabalHelper/Shared/Common.hs
@@ -1,23 +1,18 @@
 -- cabal-helper: Simple interface to Cabal's configuration state
 -- Copyright (C) 2015-2018  Daniel Gröber <cabal-helper@dxld.at>
 --
--- This program is free software: you can redistribute it and/or modify
--- it under the terms of the GNU General Public License as published by
--- the Free Software Foundation, either version 3 of the License, or
--- (at your option) any later version.
+-- SPDX-License-Identifier: Apache-2.0
 --
--- This program is distributed in the hope that it will be useful,
--- but WITHOUT ANY WARRANTY; without even the implied warranty of
--- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
--- GNU General Public License for more details.
+-- Licensed under the Apache License, Version 2.0 (the "License");
+-- you may not use this file except in compliance with the License.
+-- You may obtain a copy of the License at
 --
--- You should have received a copy of the GNU General Public License
--- along with this program.  If not, see <http://www.gnu.org/licenses/>.
+--     http://www.apache.org/licenses/LICENSE-2.0
 
 {-|
 Module      : CabalHelper.Shared.Common
 Description : Shared utility functions
-License     : GPL-3
+License     : Apache-2.0
 -}
 
 {-# LANGUAGE CPP, DeriveDataTypeable, OverloadedStrings #-}
diff --git a/src/CabalHelper/Shared/InterfaceTypes.hs b/src/CabalHelper/Shared/InterfaceTypes.hs
index 352deb0..8588c98 100644
--- a/src/CabalHelper/Shared/InterfaceTypes.hs
+++ b/src/CabalHelper/Shared/InterfaceTypes.hs
@@ -1,25 +1,20 @@
 -- cabal-helper: Simple interface to Cabal's configuration state
 -- Copyright (C) 2015-2018  Daniel Gröber <cabal-helper@dxld.at>
 --
--- This program is free software: you can redistribute it and/or modify
--- it under the terms of the GNU General Public License as published by
--- the Free Software Foundation, either version 3 of the License, or
--- (at your option) any later version.
+-- SPDX-License-Identifier: Apache-2.0
 --
--- This program is distributed in the hope that it will be useful,
--- but WITHOUT ANY WARRANTY; without even the implied warranty of
--- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
--- GNU General Public License for more details.
+-- Licensed under the Apache License, Version 2.0 (the "License");
+-- you may not use this file except in compliance with the License.
+-- You may obtain a copy of the License at
 --
--- You should have received a copy of the GNU General Public License
--- along with this program.  If not, see <http://www.gnu.org/licenses/>.
+--     http://www.apache.org/licenses/LICENSE-2.0
 
 {-# LANGUAGE DeriveGeneric, DeriveDataTypeable, DefaultSignatures #-}
 
 {-|
 Module      : CabalHelper.Shared.InterfaceTypes
 Description : Types which are used by c-h library and executable to communicate
-License     : GPL-3
+License     : Apache-2.0
 
 These types are used to communicate between the cabal-helper library and helper
 executable, using Show/Read. If any types in this module change the major