lnav.org syntax files for Atlassian log files.
To install, places these files in your ~/.lnav/formats/installed/ directory, which lnav should have created.
Very much a work in progress. Currently understands atlassian-jira.log, and enables the access_log format to understand the Apache LogFormat I use:
LogFormat "%v:%p %a %{X-ASESSIONID}o %{X-AUSERNAME}o %t \"%r\" %>s %O \"%{Referer}i\" \"%{User-Agent}i\" %D" vhost_combined_timed