The tinkerer in me just couldn’t stay away. I saw a reference on Linux Weekly News to DietLinux and had to look at it.
DietLinux is an example of a Linux distribution that can’t properly be called GNU/Linux, because the majority of its userspace didn’t come from the GNU project. GNU’s libc–the main API for Unixish systems, and I’ll call Linux a Unix just to hack off SCO–is replaced with an alternative, trimmed-down libc called dietlibc. It’s not feature-complete but it’s tiny. Those of you who programmed casually in the 1980s and 1990s probably remember a day when you could write a fairly sophisticated program in a few kilobytes. Under modern operating systems, a simple program that simply emits “Hello, world!” can take up 32K or more. Using dietlibc instead of GNU’s libc shrinks that program back down to a couple of kilobytes.
The majority of DietLinux’s userspace comes from Felix von Leitner, the author of dietlibc. Von Leitner reimplemented init–the program that bootstraps a Unix system once the kernel is loaded–and getty, which is the program that handles text-based logins. These unglamorous programs can eat up a fair chunk of memory, and since Unix systems typically go for long periods of time without being rebooted, it’s a bit of a waste unless you need certain features provided by the more traditional init and getty programs. He also wrote replacements for several standard utilities.
Obviously, not every program in the world designed for glibc will compile and run under dietlibc, so DietLinux won’t ever be a complete general-purpose distribution. But for network infrastructure glue-type servers providing services like firewalling, DNS and DHCP (all of which already function), it would be perfect.
I don’t know what the future plans for DietLinux are. The asmutils provide an impressive number of userspace and server utilities, written in assembly language with very low overhead, and would appear to be a nice complement to DietLinux’s infrastructure. Their use would limit DietLinux to x86, however. And the text editor e3 is tiny, full-featured, and emulates keybindings for vi, emacs, WordStar, and Pico, so it’s friendly to pretty much any command-line jockey regardless of heritage and takes little space.
It’s also not a newbie distribution. Installation requires a fair bit of skill and pretty much requires an existing Linux system to bootstrap it.
But it’s definitely something I want to keep an eye on. I’m highly tempted to put it on one of my 486s. I just wish I had more time to mess around with it.