As a general rule, any linux application should run under UML, with the exception of applications that directly access hardware. The following lists are of applications that someone has actually gotten running, or has confirmed failure, inside a UML instance.

Here are applications that are known to work with recent UML kernels. The version number does not indicate that this is a minimum version, just that this version is definitely known to work.

ApplicationVersionReported by Notes
Apache 1.3.22 WLS
apt 0.5.4 DC
Bash 2.05 WLS
Bind 9.2.1 WLS
Bitkeeper 2.1.6-pre5JD
Boa 0.94.13BT
Courier IMAP/POP1.5.1DC
dpkg 1.10.9 WLS
Eterm 0.9.2 DC
freeswan 1.9.6 DC
gcc 3.2.1 DC
ghostscript6.52 BT
gnupg 1.2.0 DC
Half-life server4.1.1.0WLS
HTML-Embperl1.3.4 BT
Imap/ipop 2001a WLS
iproute 20010824DC
iptables 1.2.5 WLS
lsof 4.51 WLS
mc 4.5.55 WLS
mcedit 4.5.55 WLS
mod_perl 1.27 BT
Mozilla 1.2.1 DC
Mrtg 2.9.17 DC
mtr 0.51 DC
mutt 1.4.0 DC
MySQL 3.23.52BT
netstat 1.42 WLS
Openssh 3.3p1 WLS
openvpn 1.3.0 DC
P0f 1.8.1 WLS
Perl 5.6.1 DC
Perl 5.8.8 BT
php 4.3.0 DC
PHP-Nuke 6.0 BT
Pine 4.44 WLS
pptpd 1.1.2 DC
ps 2.0.7 WLS
Python 2.1.3 DC
qmail 1.0.3 DC
red-carpet 1.4.2 WLS
route 1.98 WLS
rpm 4.0.4 WLS
Rsync 2.5.4 EW
Samba 2.2.3 DC
Sendmail 8.11.6 WLS
Squid 2.4.STABLE6WLS
Tomcat JD Needs kernel >= 2.4.19-35um
top 2.0.7 WLS
UML itself JD UML can actually run inside itself.
vim 6.1 DC
VNC 3.3.3? DC
vtund 2.5 DC
Wu-ftpd 2.6.1 WLS
Xnest 4.1.0 WLS Networking must be working first.
xchat 1.8.9 DC
xntp 5.93 WLS
xterm 4.1.0 DC
zebra 0.92 DC

Here are applications that are known to NOT work with UML:

ApplicationVersionReported by Notes
hwclock/clock WLS Accesses IO ports directly, no clock app needed in uml.
XFree86 servers WLS Talk directly to hardware, use XNest or VNC instead.

Contributions and corrections to any of the above are welcome! Please send them to William Stearns