*`junit` writes xml that corresponds to Ant's [junitreport](http://help.catchsoftware.com/display/ET/JUnit+Format) target. Useful for build systems that understand Junit. If you are using Jenkins with Catch 1.x, you can improve quality of output by applying changes in [#923](https://github.com/philsquared/Catch/pull/923).
Because of the way the junit format is structured the run must complete before anything is written.
*`xml` writes an xml format tailored to Catch. Unlike `junit` this is a streaming format so results are delivered progressively.
There are a few additional reporters, for specific build systems, in the Catch repository (in `include\reporters`) which you can `#include` in your project if you would like to make use of them.
*`teamcity` writes the native, streaming, format that [TeamCity](https://www.jetbrains.com/teamcity/) understands.
Use this when building as part of a TeamCity build to see results as they happen.
*`tap` writes in the TAP ([Test Anything Protocol](https://en.wikipedia.org/wiki/Test_Anything_Protocol)) format.
*`automake` writes in a format that correspond to [automake .trs](https://www.gnu.org/software/automake/manual/html_node/Log-files-generation-and-test-results-recording.html) files
You see what reporters are available from the command line by running with `--list-reporters`.
By default all these reports are written to stdout, but can be redirected to a file with [`-o` or `--out`](command-line.md#sending-output-to-a-file)
## Writing your own reporter
You can write your own custom reporter and register it with Catch.
At time of writing the interface is subject to some changes so is not, yet, documented here.
If you are determined you shouldn't have too much trouble working it out from the existing implementations -
but do keep in mind upcoming changes (these will be minor, simplifying, changes such as not needing to forward calls to the base class).