Top 20 NuGet contract Packages

Design by contract programming support
Base classes (like suits, ranks, cards, auction, play, contract) that are helpful in creating a bridge card game.
Puresharp API .NET 4.5.2+
IPuresharp urbanize libraries with strategic private code to lay transparent foundations for Puresharp API .NET 4.5.2+
Contracts ensuring, Messanging, LINQ expression parser and extension methods, Task Parallel Library helpers, Type auto-mapping for storage and benchmark.
A simple tool for unit testing Stratis smart contracts.
This Guards project is a light-weight toolbox which helps you to protect your public interfaces against invalid parameters being passed over.
A simple but flexible parameter validation library.
A high-performance, extensible argument validation library.
NeoSharp Virtual Machine Interop.
NEO lightwallet / blockchain API for C#. Allows you to interact with smart contracts in the NEO blockchain.
C++ Virtual Machine compatible with NEO standard.
boost_contract-vc141. Compiler: Visual Studio 2017 15.7.4.
A NEO blockchain development toolkit that does not rely on block synchronization, including transaction construction, address translation, signature, etc.
A NNS development toolkit
boost_contract-vc140. Compiler: Visual Studio 2015 Update 3.
The Schema Checker for the Consumer Schema Tool