Running ASP.Net on a Linux based server

So I know this is an older question but I think it could stand an updated answer.

Microsoft has officially released asp.net vnext and its open source and deploy-able to both Linux and Mac. Its all still pretty new but does rely on the latest builds of mono and thus currently needs you to compile the mono-framework but in time I suspect that it will be easier to access as various linux distros release updated versions of mono. This is a how to setup guide

This information may be somewhat volatile and with updates is due to change.

Update ASP.NET CORE 11/10/2017

• asp.net vnext is now known as asp.net core.
• asp.net core is being treated as a high priority in Microsoft due in part to its use with microservice architecture and docker and container technologies
• It has become much more compatible with existing .net libraries due to .net standard 2.0.
• It performs well when compared to other technology stacks such as go and node.js

It depends what specific .NET technologies you're using. The Mono Project provides an Apache module (mod_mono) for running ASP.NET sites, and from what I gather it works well.

Mono doesn't support all the .NET APIs, though - notably WPF (and possibly WCF too, I can't remember) - but it does provide good support for much else of the framework.

If you're starting from scratch and particularly want to target non-Windows servers, then ensuring your project works with Mono would be a good goal to aim for. However, if you need particular APIs or language features that are not supported by Mono, then you will need to use a Windows server for deployment. It's a design-time/architectural choice that should make up front.

You might want to consider this guide that helps Windows developers port their code to Mono/Linux:

Guide: Porting ASP.NET Applications - Mono