Just to give you a taste of one complexity: Plugins (even the builtin ones powering Studio behavior) are updatable separate from the main Studio release, so we would have to be a lot more deliberate with how dependencies work if they were not always directly bundled into the plugin.
The current solution of duplicate directly bundled dependencies is obviously unsustainable long term, but non-trivial engineering work remains to move away from that.
I imagine an engineer would have a better insight into why this is, exactly but based on what I know I can make a guess:
Roblox doesn’t have the luxury of always updating plugins to use the latest version of their packages and CorePackages is only a solution if that is always true. You have to remember that some of their plugins are very old and span multiple major versions of things like Roact. While I’m sure everyone would like them to be on the same versions, that isn’t practical sometimes.
Atop that, it is a potentially attack vector to load privileged code from the datamodel. It can be mitigated (quite easily, actually) but once upon a time it was a lot easier than it is now. That could have something to do with it, though I’m guessing not really.
See also what Stravant Tnavarts said. It adds yet more complexity with updating things, including plugins and packages.
This is awesome!!
Running play solo doesn’t make my neighborhood’s lights flicker anymore
What kind of improvements (besides plugins) made this possible?
Does it cache things like texture & mesh data?
I’m guessing there was also just a lot of piled up debt that someone was able to properly investigate
Fantastic work on this!
I know some people earlier are implying that it’s only a “small” improvement to a development pain, but a dozen manageable pains add up to become a real impediment to a good workflow. Kudos to the people behind this 
Just because we’re all used to a certain speed of development doesn’t mean we shouldn’t appreciate the work that goes into making it better. When I started developing on Roblox in early 2012, Studio looked originally like this:
It would crash constantly, and didn’t have any of the features people rely on today like the ribbon or functional local testing. People should remember that the attention to detail by engineers into small, annoying bugs is sometimes more important in the long run than the big ticket features.
Yeah, the most similar thing we have nowadays to that is the RetroStudio’s place editor, where you may get disconnected randomly and there would be that topbar (also scripting is bad quality there). but it still looks like 2015-ish studio.
Good to see people actually storing pictures from old studio, properties menu, toolbox, topbar (i never had that topbar 
), and the fact that the window looks like w7 
.
That is definetly true, I don’t have any ideas on what to say, but that’s indeed true.
Gonna drop this here, as it’s unfortunately making any gains from this beta mostly moot (from my testing):
the current ribbonbar is a godsend frfr
also i was bored and was able to date that screenshot to october 2009-november2010 going by the presence of the materials, trusses, and the default font being changed
I find this interesting. Are you able to go into what was optimized to allow this to be an improvement?
That’s like believing your ping is amazing in Play Solo since both the client and the server are running on your machine. Since studio is an emulation of a game environment and not a live server, it’d be rather foolish to assume it’s an accurate representation of a live server’s network conditions in any capacity.
Does this improve also Local server (2 players) in Studio?
Any improvements to the loading times of anything in studio is welcome, especially with starting/stopping a solo test.
i have adhd, so i tend to change my focus whilst waiting for the test to load, and my loading times can be quite long. so i usually forget what i was doing and have to spend time regathering my place in the development. so if solo tests could one day be instantaneous without fail, that’d be appreciated. but every step that gets us there is appreciated as well
pushbox.wmv (1.0 MB)
the box’s movement stays completely serverside for the first 30-60 seconds of a game running, then it starts working normally
it’d be awesome if we could get the old f6 test mode back in addition to this 
I am forever grateful to all of the developers at Roblox who made this happen. Thank you. Genuinely.
This is very cool. Very fast. It would be better if it were instant.
Yay! I remember back in the day play solo load time was so fast. No loading screen, it just took you in. So glad they’re going back.
This is great! It does make me wonder though - is there any way to manually stop plugins from loading in play solo? I have lots of plugins but there are only a couple that I’d ever use while testing, so it’d be nice to be able to disable everything else if that would make a difference.
Also I’ve just noticed I can’t use the draggers while testing now, would be nice to be able to toggle those independently of everything else.
This is awesome! It’s very nice loading into my Studio version of our game at a faster rate! It may only be a few seconds faster, but it feels a lot faster and it just feels better. (And no, this is not sarcasm, I genuinely like this update 
)
Little late to the party here, but this is really great! Just tested it and you can see visible improvement. Another win from Roblox in my book. 
Woah, This makes solo tests better…