They try to use the FPC/Lazarus build process as much as possible.
Fcpupdeluxe is the latest addition that adds a GUI to ease its use.
Meant to be used side by side with other FPC/Lazarus installations. It creates a separate primary config path directory for the new Lazarus installation, so it doesn't interfere with existing Lazarus installs.
It's open source software released under the LGPL with linking exception (same as FreePascal), and contains some open source libraries with their own license.
See source files for details. All use permitted, also commercial, but no warranties, express or implied.