All about C#

Summary of versions

C# 2.0
Generics Partial types Anonymous methods Iterators Nullable types Getter/setter separate accessibility Method group conversions (delegates) Co- and Contra-variance for delegates Static classes Delegate inference
C# 3.0
Implicitly typed local variables Object and collection initializers Auto-Implemented properties Anonymous types Extension methods Query expressions Lambda expressions Expression trees Partial methods
C# 4.0
Dynamic binding Named and optional arguments Generic co- and contravariance Embedded interop types ("NoPIA")
C# 5.0
Asynchronous methods Caller info attributes
C# 6.0
Compiler-as-a-service (Roslyn) Import of static type members into namespace Exception filters Await in catch/finally blocks Auto property initializers Default values for getter-only properties Expression-bodied members Null propagator (Succinct null checking) String Interpolation nameof operator Dictionary initializer C# 7.0 Proposals Declaration expressions Parameter arrays for IEnumerable interfaces