When comparing Fossil vs JIRA, the Slant community recommends Fossil for most people. In the question“What are the best bug/issue tracking tools for small development teams?” Fossil is ranked 10th while JIRA is ranked 16th. The most important reason people chose Fossil is:
If you need a (distrubuted) SCM, Fossil comes with a built-in SCM, a wiki and issue tracker.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro DSCM + issue tracker + wiki
If you need a (distrubuted) SCM, Fossil comes with a built-in SCM, a wiki and issue tracker.
Pro Self-contained file
The data is stored in one single file. No file structure distributed over a bunch of folders.
Pro Multi platform
The executable is provided for multiple platforms, e.g. Linux, macOS, Windows.
Pro Easy to install
The Fossil application contains one single file. No need to install dependencies.
Pro Lots of integrations and plugins
It integrates well with a lot of other tools, including other products from the Atlassian suite. Plus there are a ton of plugins, including charting tools, screen capture, etc.
Pro Backed by a trustable company
Jira is developed and maintained by Atlassian, which is not an unknown venture, especially for developers. Atlassian has a great number of other products used by million of users worldwide, including BitBucket, HipChat, Confluence and Stash.
Each of these products have hundreds of thousands of users who use them daily and this has allowed Atlassian to garner a lot of goodwill from the dev community.
Pro Very cheap for small teams
Pro Supports version-focused work-flows
JIRA is not a plain long list of tickets, but can be configured to be version-focused, so planning and understanding the progress in a software project becomes clear.
Pro Great reporting tools
Jira offers amazingly powerful reporting tools like activity stream, different graphs of opened and closed issues over time etc...
Cons
Con Ticket comments can't be edited
While a ticket can have multiple comments added to it, and (separately) also attachments — if the users have the right permissions — it is impossible to edit a comment after submitting it. This is probably why a comment must be previewed before it can be submitted.
Con New releases often change the GUI largely
Sometimes the usage becomes worse, e.g. when creating a new ticket, you need to click the notification to keep it on the display.
Con Locks you inside its own ecosystem
If you use Jira you are pretty much locked inside their ecosystem. For example, if you want to add a tool to your project management stack (like a wiki) more often than not you will have to buy one of Atlassian's tools.
Con Client application support
No free client applications; IDE connector development was discontinued. Users are effectively locked into using web interface which requires context-switching.