MPS enables me to build standalone IDEs (see https://confluence.jetbrains.com/display/MPSD34/Building+standalone+IDEs+for+your+languages), however Windows builds would definitely need a JDK/JRE. The users get confused with installing Java, etc.
- Are there "pre-built" JDKs compatible with MPS (IntelliJ platform)?
- What are the approaches to update the bundled Java? IntelliJ platform does have an updater, however does it support updating the Java runtime? The updater is Java-based, so I wonder how does it update Java runtime when using the same runtime.
- Can something like JetBrains Toolbox to manage updates of the "third-party" MPS-based IDEs?
PS. I'm using for MPS 2017.3, mbeddr if that matters.
I'm not exactly sure if the are publicly available but you can check JBs teamcity at teamcity.jetbrain.com where all their open source stuff is available.
The updater for intellij performs incremental updates to the jar files. It is not open source and it usually only used to do small updates. If there is a major update like new platform with a bunch of API updates it is not used and the user has to download complete new installer. In MPS the incremental updater is not used. So each MPS updates is complete new IDE to be downloaded by the end user (or JB toolbox).
I don't know how the JB toolbox works but you can use MPS/IntelliJs normal update mechanics to notify users about updates to your custom IDE. In the branding you create for your custom IDE there is field where you can point it to a update location. Which then serves a xml file with the update information. The format is pretty straight forward. Here is a sample. Your IDE will check on start up or at least once a day if an update is available.