Be careful of the license you agree to when using vendor SDKs.
I haven't seen the license on the Corel stuff, but I've heard
of similar situations (3Dfx and GLIDE come to mind) where an
agreement to the license terms for using the SDK prohibits
the use of any information or resources within for competing
products or even any and all published work. Supposedly 3Dfx's
GLIDE SDK license agreement kept the programmer from writing a
simple wrapper library for GLIDE (their proprietary but documented
and freely available hardware-level 3D graphics library).
I could very easily imagine a large company that sells proprietary
software products becoming very protective when it came to
their proprietary formats. The last thing I'd want is for someone
to agree to an SDK license which voids months' or years' worth of
hard work under some arm-twisting from lawyers. Maybe I'm
wrong and Corel has adopted a very open and adaptive attitude towards
their word processor format.
Either way, an import for Word Perfect would be great. As far
as I know, as many as three other people have expressed interest
in working on a Word Perfect filter. If anyone else on the list
has been keeping track of those contact addresses, now would be
a great time to pass them around again.
If you're looking for information on AbiWord's importer and
exporter interfaces, look at abi/src/wp/impexp. The base classes
(from which specific importers and exporters derive) are there
and are pretty self-explanatory. To start, I would recommend
cloning an existing filter (say the "plain text" one) and using
other filters as guidelines. Our native format is a good example
in callback-driven I/O (using expat), the plain text importer shows
a simple single pass at filling a document.
-- Shaw Terwilliger