Use other catalog formats in Maketext
locale_maketext_extract-1.00-1-any
This module can extract translatable strings from files, and write them back to PO files. It can also parse existing PO files and merge their contents with newly extracted strings.
A command-line utility, xgettext.pl, is installed with this module as well.
The format parsers are loaded as plugins, so it is possible to define your own parsers.