We actually already had "Flash for the desktop". It was called Adobe Flex (originally Macromedia Flex, and today Apache Flex), and it was... not half bad, actua

We actually already had "Flash for the desktop". It was called Adobe Flex (originally Macromedia Flex, and today Apache Flex), and it was... not half bad, actually. It was based on Adobe AIR, a cross-platform VM that used ActionScript as the language, which at the time looked a lot like what ES2015 is today -- Adobe basically tried to make ActionScript the same as "ES 4.0", an effort to add classes, properties and private/public visibility to JavaScript that was eventually abandoned in favour of smaller improvements in what became ES5, then ES2015. Flex/AIR had a pretty rich UI framework with semi-native widgets and access to the OS. It was unfortunately heavily based on declaring your UI with XML, and apps tended to look like "AIR apps", much like Swing apps look a bit off and non-native.