Since my conversation with Jeffrey Snover at the ISV CTO Summit (blogged here), I have wanted to post on some benefits of adopting PowerShell as an ISV.
Many products can be greatly improved by the addition of a rich commandline interface. Obviously this enables a user to type commands at the console, but this can also enable more advanced scripting of your application. The typical way an ISV provides such an interface is to develop a custom set of console application(s). Alternatively, a Microsoft ISV can build on top of PowerShell (using CmdLets) and get so much more.
Here are some pros and cons of these two approaches (with a nod to J. LeRoy for using Mind Maps in posts):
Custom (console applications)
Pro Multi-platform: includes any version of Windows (or anything else for that matter) that you target.
Con Design “from scratch”: Every aspect of the commandline (e.g., argument naming and syntax, formatting, etc.) needs to be designed. As there are few clear guidelines and virtually no consistency on the Windows platform, you will have to design this with a “least-worst” mindset.
Con Lots of coding: You have to write a fair amount of code for even simple use cases to enforce / interpret your arguments and to format your a report properly.
Con Advanced use cases hard (Lots more coding): Enabling complex user scenarios through your commandline may require a lot of development. For example, if you already have a rich API and want to expose this through your commandline, you may need to painstakingly map new commands to existing methods.
Con Recent Windows only: Windows XP, Windows 2003, Vista, Longhorn Server (and specifically not Windows 2000).
Pro Easy design: Since PowerShell includes clear guidance on CmdLet design (e.g., argument naming) it is much easier to design your entire commandline with few design decisions.
Pro Object pipeline. PowerShell supports an object pipeline. This greatly eases the scripting use cases. For example, instead of having to make sure that your command outputs a piece of text that can be interpreted for use in a subsequent command, you simply need to return a .NET object.
Pro Formatting. The output formatting is not only automatic but plugs directly into other PowerShell utilities to format your output as tables, lists, to sort it, etc.
Pro Advanced use cases are easy. Combining the object pipeline with PowerShell’s ability to script .NET objects, you get a commandline that enables advanced use cases without you having to design for them directly. For example, the Digipede API already enables advanced use cases. With PowerShell we don’t have to design in each of those use cases. By making it easy for a PowerShell user to get an instance of our DigipedeClient object, we have enabled all (or nearly all) of the use cases enabled through our API.
Pro Simpler docs. Less documentation needs to be written to explain the basic use cases for your interface, because of the PowerShell design guidelines.
PowerShell is a really good choice for Microsoft ISVs. It delivers a lot of value to the ISV in exchange for relatively little effort.
From my perspective, PowerShell is yet another example of how Microsoft provides a terrific platform for ISVs: we get a great command line for the Digipede Network with little effort and can focus on the core value our product brings to the market.