Paul Ramsey has been doing his usual excellent work of promoting geo-geekery by setting up a Victoria GeoGeeks Meetup. Tonight I gave a presentation on Geometry Libraries for Fun and Profit.
I was intending to give it back-to-back with a presentation on JTS, to make the whole subject more concrete - but I rambled on for so long I was yanked from the stage before I could start on the second one! That's actually good, since it will give me time to polish up the presentation a bit more. In the meantime, the current slide deck is here: JTS - A Libary for Geometry Processing.