I know I am asking for it by seeking oppionions from the Linux community as we are full of all sorts of ideas. I would like the advise from DEVELOPES ONLY. I am not looking for distro advise, nor am I looking for advise from novices. No flames either. I use Linux, but not all my clients do.

So here goes:

I would like to find an OSS replacement for MS IIS that can:
1. Work both on Linux and Windows. Either a cross platform service or one developed conjointly or seperately for both OSes.
2. Be able to use ASP.Net
3. Be secure
4. NOT BE a resource hog.

Other than that anything goes. This is your opportunity to plug your favorite product, so feel free to give as much or as little information as you desire.

Thanks.

Apache is usually the answer. Not sure about Point 2 in your list, but it fits the rest.

1) Apache is already cross-platform.

2) According to this page, Mono can do ASP.NET. There's even a mod_mono for Apache.

As for 3 and 4, I guess it depends on your idea of what secure and light-weight means. However, Apache is certainly very capable and seems to work well enough for a great number of sites. It's certainly a lot more powerful than IIS.

I was looking at the Apache web page, there appear to be alot of diferent projects. As I am not familiar with what Apache can and can not do, what project should I look at and what do I need to be able to program against the dotNET framework using Apache?

As for Mono, I have been disabled by Visual Studio. I looked at Mono Develop, but it is still missing what to me would be critical elements to productive development. For the time being, I will have to develop something in Visual Studio and then port it over to Linux. I would love to get away from Microsoft, but to be honest, Mono is a little over my head.

I know I will figure things out. I am an extremely fast learner.

Didn't read all responses you already new about mono! it might be the only acceptable answer.

Anyone ever use XSP? How does that work? I have a feeling that Apache will have a very steep learning curve. Do you think XSP will be a better starting point for simple intra net applications?

This is funny- I am asking the same questions in a Visual Studio forum, but can you guess the answers? Something like "OSS! Blasphemer! Microsoft our God will exact its revenge upon you and all your seed until the end of eternity!" I Thought Linux users had the monopoly on cult like behavior. Appears that Microsoft People do too. LOL

Seriously though, you guys have been a lot of help.

You can easily test XSP on Windows if you get the latest Mono installer. You simply start it up with a command (in this case you get a .bat that you can just click) and you can view the Mono ASP .NET test page. I didn't do much testing with it, but I assume you just drop your site in Mono's "wwwroot" equivalent (don't know what path that is) and it will automatically serve it. The usage in Linux is the same, but the installation can be a pain if you plan on doing it the hard way (if you want to build it yourself)
However, I would recommend that you used mod_mono with Apache. mod_mono uses mod-mono-server, which is a slightly modified version of XSP (there's no escaping XSP) to serve ASP .NET pages. The advantage of using mod_mono is that plain old html pages will be served by Apache (which has been around longer than XSP and we all know it's a tried and true technology).
I don't know much about XSP's reliability, performance or security though. I have a lot of interest in finding out this information but I think it simply doesn't exist yet. If you do use XSP for your projects I would be very grateful if you could share your experiences with it. good luck