From v091 to v107, higan referred to byuu’s multi-system emulator project as a whole.
In v108, inspired by the popularity of the revived bsnes, byuu added less-accurate, high-performance scanline renderers for many of the emulation cores in higan (like bsnes’ optional high-performance mode), and an alternative, bsnes-style user-interface.
Builds of v108 with both the bsnes-style scanline renderers and the bsnes-style UI were released under the project name “byuu”, and byuu renamed himself “Near” at the same time. Meanwhile, builds of v108 with the traditional dot-based renderers and the complex user-interface were released under the project name “higan”. It was possible to produce an emulator with byuu’s renderers and higan’s interface, or the other way around, although such combinations were never officially released and did not have unique names.
Thus, from the release of v108 onward:
The source-code of byuu-the-project is still part of the higan source, so look there for more information.