For the MAME 0.96 release, I added a step to the build process which runs a little tool over all the source code to ensure some consistency. A lot of people are freaking out about this in ways that are really unwarranted. You have to keep in mind that code is submitted from many people running on various platforms, and certain things like line-endings are not necessarily consistent between platforms.
For example, the file drivers/laserbas.c has had screwed up line endings for who knows how long. Diff is not the most robust tool when creating diffs against files with inconsistent line endings. When I tried to create a diff against this particular file, diff freaked, and I had to hand-modify the final patch to make it work. This was the impetus to writing the tool.
Since there seems to be a lot of paranoia about what this tool does, let me make it 100% perfectly clear. The tool does three things and only three things:
1. It makes sure all line endings are DOS/Windows standard CR/LF.
2. It removes any extra spaces/tabs at the end of each source line.
3. It converts tabs to spaces (assumes 4-character tabs) within comments. It leaves all other tabs alone.
That's it. The tool is also smart enough not to touch the file if nothing needs to be changed so that the datestamps remain consistent.
Since all the files in MAME 0.96 were updated with this tool, they will all pass unscathed when I run it before releasing 0.96u1. Which means this is really the only time you will see a significant number of changes resulting from the use of the tool. Going forward into the future, you probably won't even notice.