System.Collections.Concurrent by: Microsoft

Provides several thread-safe collection classes that should be used in place of the corresponding types in the System.Collections.NonGeneric and System.Collections packages whenever multiple threads are accessing the collection concurrently. Commonly Used Types: System.Collections.Concurrent.ConcurrentDictionary<TKey, TValue> System.Collections.Concurrent.ConcurrentQueue<T> System.Collections.Concurrent.ConcurrentBag<T> System.Collections.Concurrent.BlockingCollection<T> System.Collections.Concurrent.ConcurrentStack<T> When using NuGet 3.x this package requires at least version 3.4.

System.Configuration.ConfigurationManager by: Microsoft

Provides types that support using XML configuration files (app.config). This package exists only to support migrating existing .NET Framework code that already uses System.Configuration. When writing new code, use another configuration system instead, such as Microsoft.Extensions.Configuration.

System.Diagnostics.Contracts by: Microsoft

Provides static classes for representing program contracts such as preconditions, postconditions, and invariants. Commonly Used Types: System.Diagnostics.Contracts.Contract System.Diagnostics.Contracts.ContractClassAttribute System.Diagnostics.Contracts.ContractClassForAttribute System.Diagnostics.Contracts.ContractFailureKind System.Runtime.CompilerServices.ContractHelper System.Diagnostics.Contracts.ContractInvariantMethodAttribute System.Diagnostics.Contracts.PureAttribute System.Diagnostics.Contracts.ContractArgumentValidatorAttribute System.Diagnostics.Contracts.ContractVerificationAttribute System.Diagnostics.Contracts.ContractOptionAttribute When using NuGet 3.x this package requires at least version 3.4.

System.Diagnostics.Debug by: Microsoft

Provides classes and attributes that allows basic interaction with a debugger. Commonly Used Types: System.Diagnostics.Debug System.Diagnostics.DebuggerStepThroughAttribute System.Diagnostics.Debugger System.Diagnostics.DebuggerDisplayAttribute System.Diagnostics.DebuggerBrowsableAttribute System.Diagnostics.DebuggerBrowsableState System.Diagnostics.DebuggerHiddenAttribute System.Diagnostics.DebuggerNonUserCodeAttribute System.Diagnostics.DebuggerTypeProxyAttribute

System.IdentityModel.Tokens.Jwt by: Microsoft

Includes types that provide support for creating, serializing and validating JSON Web Tokens. As of IdentityModel 7x, this is a legacy tool that should be replaced with Microsoft.IdentityModel.JsonWebTokens.

System.IO.FileSystem.Primitives by: Microsoft

Provides common enumerations and exceptions for path-based I/O libraries. Commonly Used Types: System.IO.DirectoryNotFoundException System.IO.FileAccess System.IO.FileLoadException System.IO.PathTooLongException System.IO.FileMode System.IO.FileShare System.IO.FileAttributes When using NuGet 3.x this package requires at least version 3.4.

System.Linq by: Microsoft

Provides classes and interfaces that supports queries that use Language-Integrated Query (LINQ). Commonly Used Types: System.Linq.Enumerable System.Linq.IGrouping<TKey, TElement> System.Linq.IOrderedEnumerable<TElement> System.Linq.ILookup<TKey, TElement> System.Linq.Lookup<TKey, TElement> When using NuGet 3.x this package requires at least version 3.4.

System.Linq.Expressions by: Microsoft

Provides classes, interfaces and enumerations that enable language-level code expressions to be represented as objects in the form of expression trees. Commonly Used Types: System.Linq.IQueryable<T> System.Linq.IQueryable System.Linq.Expressions.Expression<TDelegate> System.Linq.Expressions.Expression System.Linq.Expressions.ExpressionVisitor When using NuGet 3.x this package requires at least version 3.4.

System.Memory by: Microsoft

System.Memory

System.Text.Encodings.Web by: Microsoft

Provides types for encoding and escaping strings for use in JavaScript, HyperText Markup Language (HTML), and uniform resource locators (URL). Commonly Used Types: System.Text.Encodings.Web.HtmlEncoder System.Text.Encodings.Web.UrlEncoder System.Text.Encodings.Web.JavaScriptEncoder

System.Text.Json by: Microsoft

Provides high-performance and low-allocating types that serialize objects to JavaScript Object Notation (JSON) text and deserialize JSON text to objects, with UTF-8 support built-in. Also provides types to read and write JSON text encoded as UTF-8, and to create an in-memory document object model (DOM), that is read-only, for random access of the JSON elements within a structured view of the data. The System.Text.Json library is built-in as part of the shared framework in .NET Runtime. The package can be installed when you need to use it in other target frameworks.

System.Threading.RateLimiting by: Microsoft

APIs to help manage rate limiting. Commonly Used Types: System.Threading.RateLimiting.RateLimiter System.Threading.RateLimiting.ConcurrencyLimiter System.Threading.RateLimiting.TokenBucketRateLimiter System.Threading.RateLimiting.RateLimitLease

System.Threading.Tasks.Extensions by: Microsoft

System.Threading.Tasks.Extensions

System.ValueTuple by: Microsoft

System.ValueTuple