According to http://www.mediawiki.org/wiki/Extension:SyntaxHighlight_GeSHi the mediawiki extension SVN checkout includes the geshi code. However, while SVN attempts to checkout geshi, it terminates with an error at that point.
Syntax Highlighting does not work then.
Please update the integrated geshi checkout in the mediawiki.org subversion repository.
Version: unspecified
Severity: major
For Trunk:
Subversion encountered an error:
Fetching external item into '/mnt/upload6/private/ExtensionDistributor/mw-snapshot/trunk/extensions/SyntaxHighlight_GeSHi/geshi'
svn: PROPFIND request failed on '/svnroot/geshi/tags/RELEASE_1_0_8_7/geshi-1.0.X/src'
svn: PROPFIND of '/svnroot/geshi/tags/RELEASE_1_0_8_7/geshi-1.0.X/src': Server certificate verification failed: issuer is not trusted (https://geshi.svn.sourceforge.net)
It's probably not actually an ExtensionDistributor problem, but just an issue with the server it's running on..
Fenari didn't have any certificates installed, so the error is not surprising. It's fixed now.