Clip Studio Paint

CLIP STUDIO PAINT is created by CELSYS, and is distributed to other countries by Smith Micro. At first Smith Micro distributed it with the name of Manga Studio 5, as a successor to Manga Studio 4 (which was originally called Comic Studio 4 in Japan). But because CLIP STUDIO PAINT was not technically part of the Comic Studio series, Manga Studio 5 slowly changed it's name to CLIP STUDIO PAINT (either it was something they did on their own or was forced by CELSYS, we probably will never know).

They changed it so the digital version of Manga Studio 5 would be called CLIP STUDIO PAINT while the physical edition would still be Manga Studio 5 (which resulted in mass confusion to people who didn't know that CLIP STUDIO PAINT = Manga Studio 5). Then as of ver 1.5.0+, they changed it so all versions would be called CLIP STUDIO PAINT.

Has a pretty garbage licensing scheme, limiting you to 2 installs per license. It's fine for people who only have a single machine they dual boot on or have two separate devices, but anyone who runs multiple dual-boot systems are in a heap of trouble with the licensing scheme due to the limits on deactivations.

Although Clip Studio Paint, or CSP, was originally targeted towards manga and comic artists, it has many features that are just as good or even better than popular competitors like Photoshop, SAI or Krita. For one the brush engine is great, has a big library of stock brushes and the big advantage that you can create vector strokes with any brush and any texture. This makes retroactive corrections pretty easy (NOTE: vector strokes are stil rasterized!).
What sold me was the incredibly natural feel of the brushes and blending functions. It works realisticly, actually blending the strokes and not just overlaying it, like in many other softwares. This makes painting really fun and the only programs I encountered, that did this better were Corel Painter and Paintstorm Studio.

So don't be fooled by it's label as "manga studio", it is high level software for illustration, sketching, concept art and even traditional frame by frame animation.

Not the most easiest to use, but there is many really good features. And best of all it's fast and not laggy!

After going from Photoshop, to Krita, to Corel, to Mischief and various other software, I have settled so far with Clip. It has so far the best brush engine (in my opinion) and supports a wide range of features. The documentation is also rather good, and if you ever need assets (brushes, images, 3d models etc), the community hands them out for free. If you draw, this is your call.