XLIFF support in Pootle
Pootle supports hosting XLIFF files since version 1.0. The file suffix should be .xlf. This is the recommendation by LISA.
There is a configuration option to specify if a project is using PO or XLIFF. On the project administration page there is a dropdown control where the project type can be selected. Alternatively, the option “localfiletype” can be edited in the pootle.prefs file (there is also some documentation in the pootle.prefs as we distributed it in the release package). By default projects are assumed to be PO. Remember to restart the server if pootle.prefs is edited manually.
Issues
There are some differences between PO based projects and XLIFF based projects in Pootle. In PO based projects, suggestions are stored in separate files (something like filename.po.pending), and an update / overwrite of the PO file does not affect the suggestions. In XLIFF files, the suggestions are stored in alt-trans tags, and are therefore inside the XLIFF file.