wget -O - http://winswitch.org/gpg.asc | apt-key add -
echo "deb http://winswitch.org/ VERSION main" > /etc/apt/sources.list.d/xpra.list
apt-get update
apt-get install xpra
This will install the packager's public key, add the repository to your list, update
the list of packages and finally download and install xpra.
Source and information about the original xpra version can be found here.
Note: The packages available from Debian and Ubuntu's main repositories are well out of date and do not contain many of the patches we include here.