Linkage?
Dunno, offhand. May or may not be online at the moment; too lazy to look.
Here are some other free programs that aren't specifically related to Mugen, but which I find invaluable in my Mugen endeavors:
7-Zip: Useful for creating or extracting many types of archive files, including .7z, .ZIP, .TAR, .GZ, and .BZ2, plus .RAR and .CAB (extraction only, for these two).
DGCA: Needed to create or extract .DGC and .DGD files.
GCA: Used to extract .GCA files.
PushPin: Oddly enough, Windows (as of XP, at least)
still doesn't include an "always on top" option for every window. This little accessory remedies that.
CRC Shell Extension: An Explorer shell extension that adds a file properties tab which reports the CRC32 sum of the given file. Useful for checking whether two similar files are truly identical or not.
DMEX: An Explorer shell extension that adds a multitude of right-click functionality (nested within a submenu, don't worry), including the abilities to:
- copy a list of all selected filenames to the clipboard
- open a DOS window at the selected directory
- fully expand or collapse the selected directory tree
- and do various other stuff.
Alternatively:
CmdHere Power Toy: If the "open command window here" feature is the only DMEX feature you want, just get this instead.
Notepad++: If you're still using Notepad, WordPad, or Word to edit all code files, you're an ignorant fool, I say. =P
MinGW Developer Studio: Much like Microsoft's Visual C++ 6, but free. Like Microsoft's old IDE, it includes a useful find-in-multiple-files feature.
(Unfortunately, this feature doesn't have a keyboard shortcut assigned to it, and doesn't remember the most recently used directories between sessions, so please tell us if you know of a superior alternative. Is Microsoft's Visual Studio Express an acceptable replacement, perhaps?)KDiff3: A text file comparison utility, capable of both 2-way and 3-way comparisons. Invaluable for keeping track of multiple versions of the same documents or code files. (Note that it occasionally detects differences where none exist when dealing with multibyte character encodings.)
WinMerge: Another text file comparison utility. Only does 2-way comparisons, but seems to handle multibyte characters better than KDiff3.
Since these two programs do use different comparison algorithms, there may be some cases where either one or the other's algorithm is preferable, so you may want to give both programs a try even if multibyte characters or 3-way comparisons are irrelevant to you.
GIMP: Photoshop for idealists and the poor, I guess. Inadequate or inefficient for certain Mugen-related graphics tasks, but sufficient for certain others.
MP3Gain: Like mpTrim, useful for losslessly normalizing the volume of MP3 files.
mpTrim: Like MP3Gain, useful for losslessly normalizing the volume of MP3 files.
EncSpot: Useful for viewing MP3 file statistics, and comparing different encodings of the same tracks.
HxD: The best free hex editor I've found. Lacks certain features found in
AXE, but has a nice tabbed MDI, and should be adequate for most hex editing tasks.
UPX: You'll need to use this to decompress the executable file if you intend to hack Linux Mugen to fix the AI.Cheat bug for me.

Does anyone want a similar list of programs for GNU/Linux? (It'll be sparse, if it comes from me.)
Suggested additions/modifications/replacements are welcome, of course.