The Mozilla Ubiquity project now (as of 0.5) has a fully "natural language" parser ... with official standard verbs. A lot like PowerShell ... but with a much more robust (natural language) parser. Not much need to learn syntax here.
ServiceStack JsonSerializer is based on JSV (the fastest text serializer for .NET), and is over 3.6x times faster than the BCL
JsonDataContractSerializer and is around 3x faster than NewtonSoft JSON.NET (the previous fastest JSON serializer benchmarked).