We still have some (now very old) Plone 2.1 sites running. Up until Ubuntu 8.10 python2.3 was still available from package management (albeit with limited support), but as of Ubuntu 9.04 python2.3 was removed entirely.
To recreate a development environment for these older sites means downloading Python 2.3 and compiling it by hand. Unfortunately it’s not a default build any more – as it says on the download page:
Since the release candidate, we received various reports that the this release may fail to build on current operating systems, in particular on OS X. We have made no attempt to fix these problems, as the release is targeted for systems that were current at the time Python 2.3 was originally released. For more recent systems, you might have to come up with work-arounds.
For Ubuntu 9.10 (Karmic Koala) to compile python2.3 you’ll need to disable buffer overflow checking by doing the following:
wget http://www.python.org/ftp/python/2.3.7/Python-2.3.7.tgz tar zxvf Python-2.3.7.tgz cd Python-2.3.7 ./configure --prefix=/usr/local BASECFLAGS=-U_FORTIFY_SOURCE make sudo make install
update: this post has been translated into Belorussian if you prefer that.