UO Fiddler – This is the best program for viewing and doing some quick editing of all the MUL files. Can be for anything form viewing the game artwork to adding new animations. This is a very handy program.
InsideUO – This program is an alternative to UO Fiddler. It’s a bit older and does not read the newest game MUL files. But it still can be handy.
Mulpatcher – This is the best program for doing lots of editing to the MUL files. It’s a bit tricky to figure out at first but it’s by far the best program for editing everything. It can view and edit all of the MUL files.
PandorasBox – This program is primarily for decorating though it can do some other stuff.
UO Architect – This program is awesome. It lets you build buildings and then import then into the game. You can also export static building into a UOA file.
UO Landscaper – Program used for editing the map.
CentrED – This is a program is used for editing the map files. It’s a little tricky getting it all setup but once you do it up and running you can edit all of the map.
World Maker – This program is similar to CentrED. It allows you to edit the map maps.
Gump Studio – This program allows you to build gump and then save them as file or scripts for use in your server.
Region Editor – This program should allow you to edit regions. It does not work with the newer RunUO server version so we have not used it. But I think it should work fine with older server versions.
RadMap Copy – This is an older program used for copying parts of the map.
RadMap Worldforge – This is an older program that is used for manipulating the map.