2010-05-07 ago output symbolic pretty printing markup and format in the front end;
2010-01-04 ago report keywords as singleton messages, control message kind via print mode;
2009-12-30 ago simplified init message -- removed redundant session property;
2009-12-29 ago removed slightly odd Isar_Document.init;
2009-12-17 ago simplified message format: chunks with explicit size in bytes;
2009-10-27 ago non-critical output -- ship message in one piece;
2009-09-30 ago actually perform Isar_Document.init on startup;
2009-09-29 ago explicit indication of Unsynchronized.ref;
2009-06-25 ago renamed IsabelleProcess to Isabelle_Process;
2009-06-02 ago IsabelleProcess: emit status "ready" after initialization and reports;
2009-02-28 ago moved isabelle_process.ML, isabelle_process.scala, isar.ML, session.ML to Pure/System/ (together with associated Isar commands);