Installing and upgrading help

I think you have some wrong information.

1.9 and 2.0 are not being discontinued. Their support is being reduced to security bugs only. There will be big sites running 1.9 for several years to come I am quite sure.

On the 'zend' front - I really don't understand what you mean. Zend is a company providing PHP services. Can you show me what information you read about Moodle 2.1/2.2 'requiring Zend'...

If you mean the Zend Optimizer then the answer is no, Moodle doesn't need that (for any version).

_Lifecycle_? Are we becoming theological? Sounds to me like 2.0, 1, 2 ... are the reincarnations of 1.9. Sorry, those were the days of Maya and Veda. Today's software go straight to Nirwana, also called EoL (End of Life).


Coming back to your immediate concern:
You wrote:
> Now I see you are about to discontinue moodle 1.9 and 2.0.

Did you mean http://docs.moodle.org/dev/Releases ? Then it says under 1.9, "Bug fixes for serious security issues in 1.9.x by Catalyst IT will continue until Dec 2013 (6 years)". You can find the details here: "Moodle end of life 1.9 plans" http://moodle.org/mod/forum/discuss.php?d=196713.

> The problem is my hosting provider offers php 5.2.17 with Zend or php 5.3.x without Zend. As moodle 1.9 and 2.0 require Zend, I can't install moodle 2.1 or 2.2...

Whatever "Zend" is, it is highly adviced to do a test migration first. By that I mean duplicate your Moodle and migrate that first. One step migration from 1.9 to 2.2 is supported. Check http://docs.moodle.org/22/en/Upgrading, http://moodle.org/mod/forum/discuss.php?d=195460&parent=853866 and for more explanations, "Continuing on Upgrade docs" http://moodle.org/mod/forum/discuss.php?d=197602.