Zynga used Flash for the same reason everyone else uses Flash -- ubiquity and consistency. HTML 5 canvas/JS would require divergent codepaths for each browser s

Zynga used Flash for the same reason everyone else uses Flash -- ubiquity and consistency. HTML 5 canvas/JS would require divergent codepaths for each browser since they all implement different subsections of the spec (occasionally in different ways) and would still probably require a Flash fallback for IE users (most of Zynga's target audience). It would be nice to get automatic compatibility with anything that runs a modern web browser, but the sad reality is that most PCs don't use a modern web browser, and HTML 5 doesn't really simplify anything. Flash runs the same everywhere from only one codebase.