When I am writing PHP i find it really hard to keep track of all the changes/bug fixes I make.
When you are creating a script in PHP what do you use to keep a track of any changes that you make along with adding version numbers and maintaining a changelog file?
Thanks in advance.
Use Versioning system. One of the most common is for example Subversion.
http://subversion.apache.org/
Subversion offers great features, like revision history, comparing between those revisions, also branching and tagging