Mono wasn't abandoned so much as "code merged" (a beauty from that both are now open source). Mono merged into the main .NET repo and the best parts of it becam

Mono wasn't abandoned so much as "code merged" (a beauty from that both are now open source). Mono merged into the main .NET repo and the best parts of it became "a single runtime". There are still useful parts of Mono left that aren't exactly inside the "a single runtime" yet, but the amount of "Mono code" shrinks with each version and the more it is all "just" .NET.