R1 will be ready when there are no bugs left in the R1 milestone. Until then we try to have about a beta every year.
Given the way we are organized (people working on their free time and on various topics depending on their motivation) it is hard to make any prediction in terms of time. But with about a thousand tickets in the R1 milestone, and the fact that new tickets keep being added to it, it may still take a few years. Also it seems every beta gets us some outreach which results in a few hundred new tickets being added.
My advice is: don’t wait for R1. R1 is when Haiku is finished and the version enters some kind of maintenance mode, or, to word it in another way, it starts being obsolete and deprecated as works being on R2 which will rework and replace a lot of things. There is no need to wait for that to start using it.
So, what’s next after beta3? Beta4.
An important detail about the “march 2021” date. I set that on my own without asking anyone when creating the beta3 milestone. It does not reflect anything, I just created the milestone in march this year and added 1 year to the date. Also, at this point, there has been no discussion of any beta3 plans, so the list of tickets put in that milestone is just things that didn’t get done in time for beta2, and some things that were identified as “pain points” in the beta2 release (by looking at people reviewing Haiku, for example).
Beta3 is the first release where we consistently put closed tickets in the milestone. This will give us a better overview of how many tickets we can close in a release, and help with future planning and forecast.