I have taken the GalCivII XML files and I have processed them with XML tools to generate hundreds of well-indexed HTML. Currently, the HTML has not just the techs, but the ship parts, starbase modules, and planetary improvements covered and hyperlinked. You can link from one tech to the tech that requires it or the one that it requires. There are some improvements to be made (you can't go from one module to the one that requires that module, but that's not a hard change), but you can link back and forth between the tech that provides a thing and the thing itself.
The HTML is stored in the 4 directories in the zip file. In each directory, among other things, is an index.html file. Openning this will give you a list of all the items of that particular type. If you open up the Technology list index, you'll get a special treat: not only do you get the regular tech index that you get on every other page, but you get a list of which technologies provide which attributes (and how much of those attributes). Want to get another +10 morale, but forgot what techs provide it? Well, now you know.
If you don't like the look of the files, I've used CSS fairly extensively, and I even have some marginal documentation on the subject (see the .txt files in the main directory), so feel free to change the look.
BTW, if these HTML files don't look right at all in your browser, it's probably because you're using Internet Explorer. Download FireFox or some other browser that has progressed into the modern era of HTML. And if I can get every GalCivII player to switch to FireFox (or non-IE browsers) by not supporting IE in my CSS and HTMLs, then I will have built my own little Temple of Rightousness.
What's next? Well, I want to improve a bit on my HTML tag generation for CSS purposes. And I want to fix some bugs, and perhaps sort the index a bit better. And I might add some more information, but that's less likely. And I'd like to improve upon the default CSS work. But that's about it. Mostly beautifying.
Note to the GalCivII team. Your file formats are not in the most easily parsable shape. I had to write different parsers for different kinds of files, but the actual differences were pretty superficial and unnecessary. And your TechTree file uses a namespace (unnamed at that. Bad developers!) which only makes it more difficult to use. Oh, and they aren't exactly the easiest XML formats to write by hand either. But I digress...