<i>Doing GUI calls is a notorious way to slow down apps.</i><p>Seriously. One notable Smalltalker sped up the compiler in VisualWorks this way. Yes, there is a compiler in Smalltalk, it just usually only compiles one method at a time, which had a lot to do with why no one noticed that printing notifications to the transcript took up most of the time. So for a bulk code load, turning off the notification sped up &quot;compile time&quot; a whole lot. In fact, the JIT-ed Smalltalk in VisualWorks actually outperformed the C&#x2F;YACC implemented compiler in a different Smalltalk.<p>Someone needs to keep track of this stuff. Why do we keep making the same mistakes over the decades? (Insert famous Alan Kay quote here.)