I installed Horde_Text_Diff, which supersedes Text_Diff. Here's the problem: when I try to use it, it gives me:
Class 'Horde_Text_Diff_Engine_Native' not found
I looked at the files, and it looks like there are fifteen or so classes that depend on each other, and none of the files include each other. Do I have to do this manually? Again, there are about fifteen files.
Is this how PEAR packages are supposed to work?
You need to use a PSR-0 compatible autoloader that automatically includes classes when they are available from your include path. Horde provides one, Horde_Autoloader.