The release includes extension modules, support for snapshot writing, and major fixes for concurrency issues. The update to to GraalVM 19 should eventually bring Windows support. For more reproducible research, SOMns comes now with a maintained artifact setup out of the box. New Features Add support for extension modules #252 Object heap serialization #278, #271, #276 Optimized tracing and restoring replay support #261, #257 Added VirtualBox artifact #296, #299 Concurrency Issues Swap tracing buffers for blocked threads #297 Renew Safepoint assumption only when invalid #291 Blocking primitives cannot participate in safepoints #288, #286 Fix object layout races #285 General Maintenance Update Truffle to >19.0.1 release #298 Update Truffle to 1.0.0-rc5 #266, #295, #267 Make the current instance of SomLanguage accessible for language server #277 VMM'18 Demo and Kompos improvements #270 Add Kent CI and update ReBench, Checkstyle, and Kompos dependencies #258 Improve readability of Travis CI Logs by using folding #281 Update basic-setup documentation #284 Update list of publications in README #283 Use CompilerDirectives::castExact instead of ValueProfiles #256 Move Actor mailbox loop to Truffle #250 Change Warmup in harnesses to simply disregard measurements #249 Remove All.ns #248 Bug Fixes Set promise data fields to null on resolution #300, #294 Fix Travis Error codes and Codespeed URL #287 Minimize the Truffle-related building #282 Remove dead code #275 Fix potential NPE in ExpressionNode.toString #269 Fix replay test flakiness #268 Redesign Timer Prim #264 Trace TimerPrim #262 Ensure charAt: and file read/write are compatible with PE #260 Signal exceptions without helper methods #251, #214