Currently, it's not possible to view gzipped log file directly in a browser on fedorapeople.org. The file has to be downloaded and opened in an external application.

Example from fedorapeople.org: https://fedorapeople.org/groups/freeipa/tmp/logs/example.log.gz

Working example that can be opened in a browser: https://launchpadlibrarian.net/135423671/ubuntuone-control-panel_4.1.91-0ubuntu1_4.2.0-0ubuntu1.diff.gz

I think setting the correct mime type for certain files should do it:

Content-Type: text/plain
Content-Encoding: gzip

Ideally, this should be the case for all gzipped text files, but if there's no easy way to do it, at least *.log.gz could be served this way.