2014-11-26 ago more informative failure of protocol commands, with exception trace;
2014-11-26 ago load simple_thread.ML later, such that it benefits from redefined print_exception_trace;
2013-09-18 ago improved printing of exception trace in Poly/ML 5.5.1;
2013-09-11 ago tuned comment;
2013-07-10 ago explicit shutdown of message output thread;
2012-10-17 ago more robust cancel_now: avoid shooting yourself in the foot;
2011-08-10 ago more explicit Simple_Thread.interrupt_unsynchronized, to emphasize its meaning;
2010-10-28 ago tuned white-space;
2010-09-09 ago more abstract treatment of interrupts in structure Exn -- hardly ever need to mention Interrupt literally;
2010-05-31 ago modernized some structure names, keeping a few legacy aliases;
2009-11-11 ago admit dummy implementation;
2009-11-10 ago exported SimpleThread.attributes;
2009-10-27 ago SimpleThread.fork: uniform handling of outermost Interrupt, which is not an error and should not produce exception trace;
2009-08-01 ago renamed Multithreading.regular_interrupts to Multithreading.public_interrupts;
2009-07-25 ago tuned tracing;
2009-07-25 ago added Multithreading.real_time;
2009-07-25 ago simplified/unified Multithreading.tracing_time;
2009-07-18 ago synchronized: tuned tracing;
2009-01-19 ago removed Ids;
2008-10-13 ago added generic combinator for synchronized evaluation (formerly in future.ML);
2008-10-09 ago added fail-safe interrupt;
2008-09-16 ago Simplified thread fork interface.