Please give an opinion on developing an open source market charting and trade simulation program

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C#

.NET

I am developing a quant model for options on futures for use on a hedge fund that I hope to start. It is C# on .NET and I keep historical market data on a MySql database. Although charting is not that important to me, I do need to occasionally look at a price chart with perhaps a few simple indicators. At present I use an old version of Metastock, but the problem is that each time I want to look at some data I first have to extract from my database to ASCII and then manually import into Metastock. I thought there might be an open source charting program which I could hack into by adding my MySql access routines. A search got me to an article by Rudi Grobler How to create stock charts using the Silverlight Toolkit[^]
but I was surprised that there is so little code available in this area, and it started me thinking that maybe I should build something. I don't have the time now, nor do I know anything about the admin/red tape of starting an open source project, but perhaps my cheap & nasty program could form the basis of such a project - one day.

So to my question. What platform should I use? Is C#, .NET and Silverlight the way to go or are there licencing or other issues that I don't know about?

The most unusual requirement of such a system would be that the users would mostly be non programmers, but it would be really good if they could code their own indicators and backtesting scripts the way they are able to do with EasyLanguage on Tradestation for example. I see it as a collection of objects that they would invoke, perhaps using their own choice of Basic or C#. Is it easy enough to hide the complexity for non technical types, but still allow them to get their hands dirty, say within Visual Studio Express or the Mono equivalent?