Fast compilation is important when compilation occurs at runtime, such as query compilers in modern database systems and WebAssembly virtual machines in modern browsers.
The recent discovery of the Spectre and Meltdown attacks represents a watershed moment not just for the field of Computer Security, but also of Programming Languages.
This paper presents a personal view of the evolution of six generations of Smalltalk in which the author played a part, starting with Smalltalk-72 and progressing through Smalltalk-80 to Squeak and Etoys.
The author presents two tricks to accelerate depth-first search algorithms for a class of combinatorial puzzle problems, such as tiling a tray by a fixed set of polyominoes.