ooooold drama. Like 2008.

FOSS: DMD was always open source, but the backend license was not compatible with FOSS until about 2017. D is now officially part of GCC (as of v6 I think?), and even the frontend for D in gcc is written in D (and actively maintained).

D1 vs. D2: D2 introduced immutability and vastly superior metaprogramming system. But had incompatibilities with D1. Companies like sociomantic that standardized on D1 were left with a hard problem to solve.

Tango vs phobos: This was a case of an alternative standard library with an alternative runtime. Programs that wanted to use tango and phobos-based libraries could not. This is what prompted druntime, which is tango's runtime split out and made compatible, adopted by D2. Unforutuntately, tango took a long time to port to D2 and the maintainers went elsewhere.

gc vs. nogc: The language sometimes adds calls to the gc without obvious invokations of it (e.g. allocating a closure or setting the length of an array). You can write code with @nogc as a function attribute, and it will ban all uses of the gc, even compiler-generated ones. This severely limits the runtime features you can use, so it makes the language a lot more difficult to work with. But some people insist on it because it helps avoid any GC pauses when you can't take it. There are those who think the whole std lib should be nogc, to maximize utility, but we are not going in that direction.