Was green earlier today, guess someone will hopefully fix the red tomorrow morning :)
Travis is similar to Jenkins, but also very different.
1. Every build is run in a virtual machine sandbox so other projects tests won't affect yours (eg. files or dbs left over).
2. The full infrastructure is distributed, the web frontend has been decoupled from the workers completely.
3. All push information sent by GitHub is built by default, so no need to tell Travis to build a certain branch.
4. We use web sockets so you can see the results in realtime.
5. Hosted for free for the open source community.
The core goal behind Travis is to make it easy for open source projects to test against different environments (language versions, databases, services, env vars etc.) with the aim to increase code quality for everyone.
So comparing Jenkins and Travis (the service) is a little like comparing apples and oranges, even though they do have a lot in common.
Hope this helps,
Is there a Jenkins or Gerrit based project that does this for you?