These files are EDITED (!) PKGBUILDs for the Arch Linux distribution - use with makepkg.

These files are usually edited to accomodate a newer version of the package... fixing MD5sum, editing compile options etc. etc. Provided as-is.

I normally don't touch the version number, because that way I can get updates from the package maintainer automatically.
Most of the PKGBUILDs are probably outdated, as I rarely ever do change them. Any questions - mail me at gonX@overclocked.net