version of diff / diff3 for libc5?

I'm starting to need diff more and more in my tomsrtbt.     As far as I can 
see there isn't one.   I can't get into the mailing list archives to check - 
not.toms.net tells me
       Not Found
       The requested URL /cgi-bin/wilma/tomsrtbt was not found on this 
server

I tried building my own diff using the libc5 environment but can't get it to 
compile.    I suppose I might get there eventually but at this point - 
hoping someone can direct to me to a diff/diff3 for libc5???

John