Currently, multips is a command-line tool supporting reading of IPS patches and reading/writing its custom ZP format. The future of multips includes a GUI.
Applying a patch:
multips -a target.file patch.fileCreating a patch:
multips -merge patch.zp old.file,new.fileConvert IPS to ZP:
multips -merge patch.zp patch.ips
For additional invocation help, try multips -help.
See also the rationale behind ZP and the format specification.
(Just as a note, I don't plan to submit this as a utility to the main site. I have my reasons for this, but it's currently nearly three in the morning, so I can't re,e,ner tje.)