Here are my slides for the talk.
I said a lot of things that were not on the slides. In particular: "More foolish things have been said about APL than any other programming language, and Edsger Dijkstra was one of the biggest offenders."
In addition to the talks, there were some really nice displays from the collection of the York University Computer Museum. For example there was an IBM 5100 APL machine (one that I spend several years programming as an undergraduate), and an MCM APL machine.
We also saw a short film by Catherine Lathwell, who is working on a full-fledged documentary about APL.
At a panel we were asked to summarize what APL meant to us. I said something like the following: APL taught us that a good notation is half the battle. Computing is ultimately about insight, and a system that encourages experimentation and variation is one that can be used to treat mathematics almost as if it were an experimental science.
Thanks to Zbigniew Stachniak and Catherine Lathwell for organizing this.