Excel-DNA Roadmap Discussion

How should Excel-DNA evolve over the coming years?

I can imagine the following versions, with some features that may be progressively realised over the coming years.

### version 0.35

- [x] Improve build tasks - more reliable clean-up and debugger detection.
- [x] Improve RTD and async QueueAsMacro reliability
- [x] Improve install process of ExcelDna.AddIn NuGet package (now requires NuGet 2.5)
- [x] Call UnhandledExceptionHandler for macros (ExcelCommands) too
- [x] Change how ExcelDnaUtil.Application works in Protected View - try harder but don't cache

Released as soon as possible - end of May / early June 2018.

### version 0.36

* Increase IntelliSense flexibility
* Improved unloading support
* Improve build process (Excel-DNA itself, not user add-ins)

Some example issues:

- [ ] #67 Allow complete unloading of add-in - implement DllCanUnloadNow()
- [ ] #85 Store and return untruncated attribute descriptions
- [ ] #49 Fix AppVeyor build

### version 1.0

Final version to support .NET versions < 4.0 and Excel versions < 2007

Maybe by 2019?

### version 1.1

First version with only .NET 4.0+ and Excel 2007+, preserving interface (existing add-ins should work / easily recompile)

* Rework marshaling implementation
* Add support for high-performance marshaling with Span, in-place parameters etc.
* RTD marshaling improvements (prevent multiple result copies).

### version 2.0

Add support for .NET Core, including pre-compiled add-ins with CoreRT (also allows wabasm support for running as add-ins on other platforms).

Add-In projects might look very different, but we should try to preserve behaviour of the code as far as possible.

Maybe in the early 2020s?