Short bio: Computer Scientist, FOSS supporter (read more)
Tux Machines (TM)-specific
Do-it-yourself distributions have made great strides since Linux from Scratch, or even rPath's rBuilder Online. In the last few months, users have even been able to produce custom disk images with such tools as Fedora's Revisor and Ubuntu's Reconstructor. However, one of the most elegant tools to emerge recently is Custom NimbleX, a PHP program that allows you to construct an ISO image in your browser and then download it. Custom NimbleX lacks some polish in the interface, but is so simply and well-designed functionally that it should lead many users to NimbleX itself, the distribution on which it is based.
To judge from its forums, NimbleX has attracted a surprisingly large number of users for such a relatively unknown distribution. It's based on Slackware and includes KDE among its choice of desktops. The distribution can run from a CD, flash drive, or network, yet offers an unexpectedly rapid response time and requires only 128MB of RAM. Its package selection is well-rounded, if sometimes idiosyncratic.