to download a sources snapshot from a CVS (concurrent version system) repository:

cvs -d :pserver:anonymous@cvs.linuxtv.org:/cvs/video4linux login
(use an empty password)

cvs -z3 -d :pserver:anonymous@cvs.linuxtv.org:/cvs/video4linux co -P v4l-dvb

where -zN indicates the compression level required; -d indicates the cvs root directory; co is the abbreviation of checkout command (which can also be used); -P prunes empty directories

to download a sources snapshot form a SVN (subversion) repository:

svn checkout http://lm-sensors.org/svn/lm-sensors/trunk lm-sensors

notice the trunk directory, if you do not specify that you’ll be going to download also all previous versions’s sources!

to update:
cd lm-sensors
svn update

to download a sources snapshot form a HG (mercurial) repository:

to retrieve the source tree:
hg clone http://linuxtv.org/hg/v4l-dvb

To update the sources later on:
cd v4l-dvb
hg pull -u http://linuxtv.org/hg/v4l-dvb

some projects use for compiling script ./hgcompile instead of standard ./configure && make && make install

Related posts:

1. mixing Intrepid stable and Jaunty testing repositories
2. WINE latest repositories for x86 and x86_64
3. compiling gnome sensors-applet with nVidia support