I don't have, no know of, a test I can run against CassiniDev to test it's compliance/support with HTTP 1.1. If you do, please let me know, I would be interested.
But my gut says yes, as it is basically IIS 6 with some limitations.
Mime Types: If you are asking if CassiniDev is able to serve up content and send the correct content-type headers the answer is yes. I specifically added support for a huge array of file types. You can browse the Common.cs file and see if this answers your
Mono: Compile on mono? pretty sure that is a non-starter due to some references. Run on mono? perhaps, if you carry some of the unsupported framework binaries along with you. I have not tested this scenario.
Production: Surely you jest, sir! ;-)
CassiniDev, like Cassini and WebDev.WebServer are intended as development and/or testing tools. While you may expose content with CassiniDev on any IP and any port, to serve content to the internet at large with CassiniDev poses a security risk and this
is one of the primary reasons that the Visual Studio development server is crippled in this fashion.
And while I have not tested the throughput or connection capacity of CassiniDev or any other development/testing server I would have to make an educated guess and say that, given your stated requirements, you would be better served with a dedicated and mature
HTTP server implementation.
If you choose to test CassiniDev in this capacity, please do report back your results. I would be interested.