[TYPO3-ect] How to maintain an "orphaned" extension

[Ralf Heydenreich]

Hi all,
I'm using the extension an_predigten. Unfortunately, I can't contact the 
developer (he's not responding to my mails). It seems that the 
development was cancelled in an early state (last update was in 2008). I 
would enhance the extension, but I don't know an "official" way how to 
do this. How can I transfer the development of this extension?

TIA,
Ralf.