Cog is the open source JIT virtual machine used as standard by the Pharo, Squeak, Cuis and Newspeak platforms. It started eight years ago at Qwaq and has developed steadily since then, gaining performance, adding platforms, and becoming more inclusive of community participation. This talk briefly reviews that history, discusses work currently underway and the state of collaboration around the VM. It then looks forward to the next sets of problems to be tackled, both technical and organisational.Download presentation
He is a Smalltalk VM implementor and systems programmer having written his first VM in 1983. He worked on Peter Deutsch’s HPS VM for VisualWorks throughout the 90’s and early 2000’s and essentially double its speed (mostly by adding polymorphic inline caches and rearchitecting its mapping of contexts to stacks). He was technical lead for VisualWorks from vw 3.0 through vw 7.4.1, leaving at the and of 2006. Amongst other things he invented method pragmas/method tags as seen in VisualWorks and Squeak. He spent an all too brief but stimulating time at Cadence in Gilad Bracha’s Newspeak team, and then went to Qwaq (now 3DICC) where he implemented another fast VM for Croquet, a 3d immersive collaboration architecture built above Squeak Smalltalk, but this time (unlike VisualWorks) the VM is open source. He returned to Cadence early in 2011 where he is working half-time for Yaron Kashai on system-on-a-chip design support in Newspeak running above the Cog VM. He is also collaborating with Tudor Girba in helping companies exploit Pharo and Cog.