Lpatch

File patcher available with both GUI (on Windows) and command-line mode plus
various features. It uses some text files with the lpatch extension for the
list of operations to perform on the target file to patch.

These text files are trivial to create and edit and allow to specify comments,
the default name of the file to patch, an introduction to display before apply
the patch, MD5 hash verification, the modification of a byte at a specific
offset, the substituition of a sequence of bytes or a string, wildcards and
more.

Exists also an older version of "patch files" used for substituiting bytes at
fixed offsets and are identified by the lpatch.dat name.

On Windows the tool can also be used to patch a running process and
launching+patching it.

Installation:

Copy mlpatch lpatch SYS:C/