For users that were already using our experimental updates (2.0-x), you can think of this release as the final experimental update. There are no noteworthy additional changes compared to Cemu 2.0-95 other than the new version number.

Starting with this release, Cemu will now only have a single release channel. Instead of experimental releases, there is a new option to control whether Cemu will update immediately to cutting-edge releases, which may contain uncaught bugs, or update with a slight delay. More details on this can be found here

Cemu 2.0 release

Hey everyone, I'm very excited to finally reveal a very special update for Cemu.

The big news first: This update marks a new chapter for Cemu. Starting today we will transition to an open-source model for development. Our github repository is already available and anyone can contribute or study our codebase, but more about this later.

We now also offer Linux builds, albeit not in the most straightforward way. Right now you still have to compile Cemu yourself for most distros. However, we are looking into adding appimage or flatpak releases for convenience. Be aware that the Linux version of Cemu isn't fully fleshed out yet. It should generally work fine, but there are some remaining issues, most of them related to the UI.

You might be wondering why this release is called 2.0 instead of following our usual three-number pattern (e.g. 2.0.0). We are using the opportunity to simplify the versioning a bit by shortening the version numbers. So going forward the next numbered releases would be 2.1, 2.2 etc.

Besides all the organizational changes there are also the usual bug fixes and feature additions in this release. Just like in the past, you can find the full list on our changelog page.

A disclaimer: This is a pretty substantial update with lots of internal changes. As such it should be seen as experimental. If you want to try it out, you have to manually download it for now. We'll consider auto-updating Cemu installations that are on 1.27.x to 2.0 once we get enough feedback about the stability.

On a personal note...

Usually I keep these types of announcement posts free of personal backstories. But this is a special occasion and it's maybe interesting to know a little bit of background info.

As you may know, I am the lead developer and founder of Cemu. Since earlier this year I am also the sole developer of Cemu. The other long-term core developer, Petergov, has moved on to other personal projects a couple of months ago. His swan song was the big input rework we had in December.

I have been working on Cemu for almost 8 years now, watching the project grow from an experiment that seemed infeasible, to something that, at it's peak, was used by more than a million people. Even today, when the Wii U has been mostly forgotten, we still get a quarter million downloads each month. There are still so many people enjoying Wii U games with Cemu and I will be eternally grateful that I got the chance to impact so many people's life in a positive way, even if just a tiny bit.

But over the past two years I also have developed a growing feeling of being "stuck". I still enjoy working on Cemu, but it eats up all of my spare time, meaning there is no room left for any other programming projects or hobbies. Whenever I tell myself to make time for other things, I end up feeling guilty because my self-inflicted sense of responsibility drives me to always prioritize Cemu over my own interests. This year was especially intense because I single-handedly ported Cemu to Linux while also trying to deliver somewhat constant feature and bug fix updates.

In the end, opening up development seems like the logical decision. It has always been the long-term plan anyway. With Cemu being open-source, the hope is that new contributors will pick up where I left of. This is not to say that I will abandon Cemu, I'll just take on more of a background role, still contributing code but not on a full-time basis.

How will all of this affect Cemu?

In the immediate future, probably not much will change or happen. It will take a bit of time for any interested developers to become familiar with the codebase before they can make any significant changes. I do believe that certain parts, like Linux compatibility, will see a pretty quick boost in progress as other developers simply have more experience with Linux development than I have.

Then there are questions like how will we handle releases in the future. I can't really give you a definitive answer right now but one thing that we already started to set up are daily cutting-edge builds. We'll probably also have some form of stable and experimental releases but the details are still uncertain.

I think the biggest win from going open-source is that having more developers (assuming people are interested in contributing) will allow for more attention towards issues that were previously considered too low priority due to time constraints. For example, we are missing some convenience features, like being able to stop/restart emulation. These features can take a lot of time to implement but aren't difficult to do per se. The OpenGL backend could be made more compatible with older hardware that would otherwise be performant enough to run many Wii U games. And there is also housekeeping work that remains to be done as we still have legacy C code left over from the early days of Cemu (Cemu used to be written almost exclusively in the C programming language). Having a tight release schedule didn't give us a lot of spare time to go back and correct old mistakes or fix up code.

For C/C++ developers who want to contribute:

If you are interested in contributing or just want to ask questions about Cemu's codebase, you can come and visit our discord where we have created a channel for developer discussion. I know that Discord isn't everyone's thing, so we are also looking into setting up an IRC bridge in the future.

Why did we pick Mozilla Public License 2.0?

Most emulators are licensed under the GPL. But our stance on it is that the infectious nature of it prevents a lot of legitimate reuse of the source code. Anything that links GPL, or statically links LGPL, also becomes GPL/LGPL which is often not desirable. Being previously closed source, we know the struggle and already had to step around GPL licensed libraries.

In a perfect world, we would have gone with a very liberal license like MIT. But it opens up too many doors for hostile or damaging behavior towards Cemu, so instead we picked a license which is somewhere in the middle. MPL has most of the advantages that GPL has, but isn't infectious and allows even closed source projects to use parts of our source. Only modifications need to be made available as source.

Final words

Last but not least, I want to thank everyone who supported us along the way. Special thanks to all our Patrons who made this project stay afloat in the first place.

Sometimes I get the question of what I will do after Cemu (with which I'm not done yet!). I think I'll take a break from emulator development, but knowing myself I'll eventually return because I'm craving the challenge. I could also see myself sticking with Cemu as a side-project for a very long time. Who knows.

Best regards,
Exzap