The table below specifies the more or less concrete short-to-mid-term plans:

Needless to say, all this is heavily subject to change.

Nearly all applications are available on Windows as dual 32/64-bit installers (which automatically install the edition matching the operating system) and as 32- and 64-bit portable editions.
The exception is the Delta Framework application, which will remain available only as a 32-bit installer for the foreseeable future.
The Delta Framework application is behind the times in several other respects as well, such as:

• MIDI I/O handling.
• It is 'pre-mountainutilities.eu', thus links to the old Mountain Utilities web site.
• It doesn't provide advanced setup/desktop management yet.

The table below specifies the general plans for all applications, concerning the availability of manuals and the availability on macOS and Linux.

Linux:
At the moment no application has a Linux edition.
However, the only remaining stumbling-block is the lack of low-level MIDI I/O handling.
Once this is implemented (hopefully in early 2019), creating Linux editions should be easy, particularly for the four applications already having macOS editions, since the source code of these macOS editions can be used for Linux almost verbatim.

macOS:
Apple has started deprecating 32-bit macOS applications, such as the four Mountain Utilities applications coming in 32-bit macOS editions (as specified in the table below).
Unfortunately, the Lazarus programming language, used to create these four applications, doesn't support the 64-bit macOS interface ("Cocoa") fully yet.
Therefore work on 64-bit editions of these applications can only start once Lazarus does support Cocoa fully.
It is uncertain when this will be the case: perhaps in 2019?