I'm using it and like it a lot here are my reasons:

- I like C# as a language. It's easy to work with and the compiler catches a lot of things that would be runtime errors in php or python.

- I like Visual Studio a lot. I'm far more productive in that environment than anything else I've tried in other languages.

- For what I'm doing the cost of Windows is far less than the lost productivity working in another environment would give me.

- SQL Server 2008 is just awesome.

- Using LINQ to SQL has saved me a ton of time.

I have used .NET for all my start up endeavors. Like others have suggested, it just works for me since I have background in .NET and windows development.

Although I have experimented with Ruby and Python both I never felt like the incurring the cost of learning curve while trying to complete a project. In my opinion my customers do not care about the language the application is written in as long as they are accessing it from a browser.

One thing I want to point out is that the monthly costs for VPS are much higher compared to linux nodes and it has a significant impact on hosting costs every month.

Have you tried hosting on mono/linux? I'm curious about this, myself.

I have not yet used it because as others pointed out I rely heavily on SQL Server 2005/8 to use Linq To SQL in my solutions. Even if I can host the application on a linux box, I still need a windows box to put the DB server on.

However, I've been looking at postgreSQL for a while and it looks ok. I am curious if anyone has tried this before.

Has anyone done this with MySql/PostgreSQL?

We're using it, because we knew it, and it just works.

I agree.

(Macintosh : PC with MS Windows) in 1995 = (.NET+C# : Java) in 2010

The latter is cheaper and has more choice, but the former fits together so much better.

Perhaps a large percentage of startups are using .net but not mentioning it to HN for fear of not sounding cool like Ruby or a NoSQL platform.

We use it because we know it and can launch something fast. It does everything we need it to do, maybe the backend is not very elegant, but functionality wise, it's all there. For us, getting a userbase and revenue going is far more desirable than learning the new 'ultimate platform that scales to the universe'.

We do. It works fine, no reason to switch.

My background is Windows dev, that is why "we" choose it in he first place.

Yep, we're .NET through-and-through. Our main product is written in C#/F# and is a tool for .NET developers, and our website is built on the WISA stack.

MS has managed to recover a lot of good will in the last half decade. That probably accounts for quite a bit of it. I know I've dropped a large part of my criticisms. I'm even using Office and looking forward to my next laptop and Win 7.

And 99% of what I do is simple tools that can be done in .NET with a few libraries from Codeplex and a little UI work.

I'm not in a startup or anything, but consider this; cloud computing is gaining momentum fast, and lots of startups will use cloud platforms like EC2, AppEngine, Azure etc.

The one thing about this change is that traditional licensing concerns go away. If you use Azure, you are paying by usage, so Windows licenses aren't in play. I guess my point is that the fear of launching a startup and having to face spirling license costs (for using MS products) is going to decline as more people adopt cloud platforms.

Plus: If you go Azure where will you develop? Will some nice M$ guy install Visual Studio in the cloud and you will use remote desktop? Where will you test? No local dev servers, really?

Besides that, Azure is NOT usage payed, Azure is an approximation to that I would call scalable server rental. You pay by time and size, not by use. Maybe that explains Azure's momentum, they're getting things right and discouraging people by having expensive/inadequate prices. I hope they get it right soon, and that they start billing by usage.

I do .Net at an agency and I like it but it's amazing how much noise there is in the Microsoft ecossystem.

I would imagine the license costs for dev tools for a startup are neglible. If you run Azure you would setup test/staging instances and tear them down when not in use, again because of scale, I would imagine that cost is negligible.

As for usage costs, doesn't Azure use the same model as all the others, e.g. EC2, in that cost = compute hours (i.e. instance running) + data transfer + storage? So if by usage you mean ultra accurate per CPU millisecond billing, then I don't anyone does that? Would be great though. Happy to be proved wrong though, I'm no expert on this...

I agree that the dev tools license costs for a startup are/should be negligible, I was just pointing that Azure isn't a substitute for a dev environment (and it's licensing costs).

I also think that the problem of the production environment costs is a good one to have, nobody should fear to start a business because of them. If you can't solve that problem it means you have the wrong business model or really bad engineers.

Oops my bad, I tought others did the billing by CPU load instead of by hour.

I'm still waiting for some nice L1nux dude to come setup all my free linux servers for testing...

Plus: Compared to salaries, license costs are negligible.

Exactly....for all this FUD about licensing costs, if that's the difference between make or break, or affects your profitability in a major way, then you have a lot bigger problems than your licensing cost.

Not a startup but I'm using it. I was doing Java for awhile but we started getting into .Net at work. I happen to like it a lot better, and it works nicely for me. The only problem I have with Microsoft stuff is that it's so damn hard to keep up with the curve. I'm still learning parts from the .Net 3.5 framework and 4.0 has been out for nearly a year already...

We do, because:

1. We already know it well and it's good enough.

2. Things just work. Somehow I'm expecting to face lots of strange problems in RoR with stuff like encoding, threads, networking.