Thanks for posting this. Am surprised to have not heard of this project before. It's a bit disappointing that it's not included in either of the Distro's that I use regularly. And even worse that the source for the project is maintained in CVS. It seems like perhaps the project is a tad neglected.
Thanks for highlighting this; I took it out for a spin and wow it's fast. I normally find myself working on projects with tens of thousands of files and I've never really been happy with the few seconds it can take ctags to locate a definition or to tab-complete something. Though it seems like gtags is missing a couple of output-related options, the speed of lookup is a significant improvement.