One of the reasons I really like Nisus Writer Express for OS X is that it uses Rich Text Format (RTF) as its native file format. If you're going to use anything other than Word the application must have the option of using either RTF or DOC as its native file format. Nothing else is acceptable at this time, though one day perhaps the OpenOffice file format will see wider use.
Today I discovered a surprising downside of Microsoft's version of RTF.
I have an 849 KB Word 2003 DOC file that contains a fair number of screen shots. I know Word is very good at bitmap compression, so I just pasted them in. I didn't bother creating PNGs and importing them (PNG is by far the best standard file format for screen shots).
I exported to RTF from Word and the output file was 40 MB. Obviously the images have expanded a bit, about 45 fold! I assume they're now uncompressed.
By comparison I created a PDF, choosing "High Quality" for the JPGs. The resulting file was 735 KB, but the images showed some JPEG compression artifact; they were not nearly as sharp as the original Word file.
I'm very curious to see how large the file will be that Nisus creates. Can RTF support embedded PNGs? Will Nisus convert the native Word images to PNG?
Update 10/8/07: I tested using Nisus Writer Express, opening the .DOC file and saving it as RTF. Nisus' RTF version was 1.4MB, so it was about 100% larger. That's a lot better than the 4500% increase in Word's RTF version. I'm not sure what kind of compression NWE is using. Incidentally, NWE could not render Word's Table of Contents for this document, and every time it starts up it nags me about a PAY upgrade. Great way to really annoy the customer.