corefxlab

It means that development on Kestrel started before work on making System.Net.Sockets cross-platform was completed. The programming model for libuv and .NET Sockets is different enough (mostly in terms of threading) to make the transition non-trivial. Some recent basic testing show .NET Sockets perform at least as well as libuv. We are strongly considering transitioning Kestrel to Sockets at the same time we migrate from Streams to Pipelines. [1] Pipelines are basically push based Streams that require less total allocations to use. This is because Pipelines allow better memory sharing between producers and consumers. [1] https://github.com/dotnet/corefxlab/tree/master/src/System.I... Disclosure: In case it wasn't already obvious, I work for Microsoft on Kestrel.

In addition to the new language features there are some very exciting new APIs being designed at: https://github.com/dotnet/corefxlab Including a new higher performance/lower allocation text formatting API: https://github.com/dotnet/corefxlab/wiki/System.Text.Formatt...

ArraySegment<T> is just a array reference with range delimiters. Slice/Span gives you a low overhead, type safe window into a block of memory that can be reinterpreted without allocating new memory. It's implementation involves some IL level pointer hacks to keep it fast. Joe Duffy's first implmentation of it is here: https://github.com/joeduffy/slice.net The more recent work for CoreFX is here: https://github.com/dotnet/corefxlab/tree/master/src/System.S...

Yeah the slice stuff is pretty nice, it's actually now being developed on the CoreFX Labs[1], so it might eventually make it into the Core CLR. [1]: https://github.com/dotnet/corefxlab/tree/master/src/System.S...