CLAP is an open source plug-in format that first appeared a few years ago.
It hasn’t been officially released, but guys from U-HE are pushing it in their installers.
The main reason for the standard is that it’s liberally licensed (i.e. no fees, lawsuits, etc.)
Another reason is (allegedly) its stability.
Another pros:
Source: CLAP: Neues Open Source Plug-in-Format in Arbeit! - gearnews.de
Great (sigh) — on top of that we have to deal with
MOTU has their own format (MAS) as well
Getting a bit silly. Given that VST is an open standard, it’s a pity they didn’t just extend VST standard to add whatever new stuff they wanted.
I thought that RTAS were a legacy format, replaced by AAX.
It seems that Bitwig is also pushing CLAP.
Das sind alles Querdenker 
Yes, bigwig and uhe developed clap together. RTAS is legacy but still used by many older protools users.
Of the latter, it seems that things are moving forward:
Good news for users but additional work planned for the GP devs? 
Reaper 6.71 (2022/11/29) now manages clap plugins, whose list is growing as well as that of applications and developers.
New plugins now appear only in clap format.
More info on clapdb.tech
We probably need to wait until this format is properly supported via JUCE. That said, I think it is extremely unlikely that VST and AU formats are going away any time soon.
You are absolutely right, the only thing I hope is that the “ultimate perfect plugin” will not be released only in clap version like the last one I installed. 
I don’t know what is that particular plugin but anybody who is trying to be visible in the plugin world is not going to just release “clap only” for the foreseeable future.
New formats come and go but, for example, Logic Pro supports only AU plugins and other than the open-source people, nobody relevant is releasing a plugin without AU support, IMO
It’s a simple free FM synth from a developer who does this in his spare time, and I don’t think he’s looking for fame 
Fluctus
I guess one gets what one pays for 
If you want a really amazing FM synth, it’s worth checking out F’em (although it’s not even close to being free)
In fact I had installed Fluctus just out of curiosity for the clap format.
Thanks for the info on F.'em which seems very interesting, but for the moment, because of my budget, I won’t go near it…
I’m also used to using Dexed for years with its 16000 banks of sounds - but with lots of duplicates !
And that it because I had so much fun with my DX7s (of which I got the second copy for France in 1983 thanks to Dave Bristow).
Where it is now? I still have mine 
I believe Steinberg no longer allows free use of the VST 2 toolkit for people that don’t pay for it. I know what I was messing around with JUCE and created a couple basic VST’s just to get a better understanding of how they worked I had to switch to VST 3 because I could no longer get the required libraries.
And I suspect many of us VST users have encountered places where VST 3 versions don’t behave as the VST 2 versions did, so we still use VST 2 versions.
I do wish Steinberg would make VST 3 an “open standard” but I believe it’s more of a “free to use” standard that Steinberg tightly controls, rarely updates, and isn’t particularly open to feedback about.
All that said, I have no real complaints with VST and am not holding my breath for widespread CLAP adoption. (And did they really have to name it after a sexually transmitted disease?)
I am a guitarist and not a keyboardist at all.
I had to sell them to buy a dumble-like amp… which I sold after I had a herniated disc and discovered GP.
As MultitrackStudio, Bitwig and now Reaper support CLAP plugins we plan to release all our plugins with CLAP support soon. We hope Gig Performer will be next See also https://www.martinic.com/blog/clap-audio-plugin-format
Thank you for this state of play.
One more “standard” of plugins is not a chance, it’s a pain! Why not an outpouring of new “standards” while we’re at it… 