I think OCRed PDFs are the way to go. There are PDF readers for almost every platform out there.
There are PDF creators as well, so if it is in a different format, as long as I can print it, I can make a PDF from it. Not sure about the searchable PDFs if it is in bitmap format.
Custom EXE, why not make it in Java? Does Java exist for the Palm yet?
There are so many Traveller helper programs out there, and they are either in Windows EXE, DOS EXE, MacOS 8.X binary, Linux ELF, or some other format. It would be nice if the official MegaTraveller CD supported as many platforms as possible.
Our dear departed original GM, willed his Traveller collection to me. Including a lot of MegaTraveller books. Provided that I share them with the group. I have, but in the past people have done things like rip out parts of the MegaTraveller Player's Manual that tells how much equipment or weapons cost, or that have tables that generate characters. With PDFs or printable formats, I can print out those pages for them to take home and roll up characters and equip them. That is an acceptable use, right? I mean not the whole book, just the parts they need to roll up characters before the game starts. The people who ripped up the books and didn't return the pages (I would have gladly let them borrow the book if they promised to return it) are no longer with our group.