These are my favorite utilities.
Self-praise. I have used the Keymacs till this was born.
One of the most popular IM(Input Method) on emacs, xemacs, and mule. The development of this application is already the end, in spite of this is an alpha version. Actually, this fails in some situation. But, I can never use other IMs anymore.
Cygwin is tools to use unix command on Windows.
Artistic Style (astyle)
Automatic indentation filter for C, C++, and Java source codes. This is included in Cygwin.
Meadow / Mule for Win32
These are text editor like emacs. These are best editors if these boot fast and a user can customize easily. But I could not wait for booting time and I did not need almost all functions of emacs. So I began to use Notepad + Keymacs and after that, I bore XKeymacs. BTW, my favorite .emacs file is here.
xearth for Windows / XEarth
These are Xearth for Windows. Xearth sets the desktop window to an image of the Earth. This is the last application to be useful in all applications I use. :-)
Uncompress software. On of the first applications which are not required DLL for uncompress. The favorite point is that install is easy and archived files is put on desktop. But all string like message, menu, etc are not displayed correctly on Windows English version.
FTP Client software. The reason I use it is that my first FTP Client was FFFTP. But I never feel complaint. There is English version and the source code is opened.
SnapIt modifies window to resize the necessary and sufficient size to show all icons. Distribution and remittance of this is already end. But the author of this said "Never prohibit a private distribution of SnapIt", so the people who are interested in this, please mail me. (If I put the SnapIt here, it is not a private distribute I think. So...)
I used this to swap Ctrl with Caps Lock and swap Esc with ~/` key. Now XKeymacs has same function, so I do not use AltIme. By the way, on Windows 2000, you can set to swap the left CTRL key with the CAPS LOCK key and to make the left CTRL key the CAPS LOCK key by to modify registry. Details are here.