Ceylon was designed to run as well on the JVM as on JavaScript... there was even a community member who for some reason got really far into making it run on the

Ceylon was designed to run as well on the JVM as on JavaScript... there was even a community member who for some reason got really far into making it run on the Dart VM. It was a great language, with awesome features we still don't see in a lot of languages (the way tuples were deeply integrated into the language such that function arguments were treated as tuples, nullable types were just unions Null|T, the advanced module system, type-safe reflection which enabled stuff like type-safe keypaths which someone posted for Rust the other day, were all brilliant included in Ceylon). However, the execution was not great. There were bugs, there was no killer app/framework for it, the focus was too much on the ideas. I am quite upset it basically lost completely to Kotlin (and maybe Scala)... I invested a good deal of time learning it and that turned out to be mostly wasted time, except for a few design approaches and ideas that stick with me and can be transferred nicely to less powerful languages.