Deedle by: BlueMountain Capital FsLab

Deedle implements an efficient and robust frame and series data structures for manipulating with structured data. It supports handling of missing values, aggregations, grouping, joining, statistical functions and more. For frames and series with ordered indices (such as time series), automatic alignment is also available.

DH.MySql by: 湖北登灏科技有限公司

Pure C# high-performance MySQL ADO.NET driver. Zero third-party dependencies, full async/await, Pipelined Batch Execution for 2~3× faster batch DML. MIT license. Supports net45~net11, MySQL 5.x~9.0+, OceanBase, TiDB, Doris, Aurora, CloudSQL.

DH.NAgent by: 湖北登灏科技有限公司

跨平台系统服务与守护进程管理框架，支持安装、监控与自动重启。

DH.NCode by: 湖北登灏科技有限公司

高性能 .NET 数据中间件（超级ORM），聚焦添删改查与海量数据，内置多级缓存、自动迁移、分表分库、强类型查询与跨库迁移。

DH.NCore by: 湖北登灏科技有限公司

Core library of NewLife framework. Provides high-performance infrastructure for building scalable applications: logging (file/network), configuration (XML/JSON/HTTP), cache (memory/distributed), network (TCP/UDP/HTTP/WebSocket), serialization (binary/XML/JSON), APM tracing, IoC container, actor model, timer scheduler, plugin framework, and more. Supports .NET Framework 4.5 to .NET 11. 核心组件库，为构建可扩展应用程序提供高性能基础设施。提供日志（文件/网络）、配置（XML/JSON/HTTP）、缓存（内存/分布式）、网络（TCP/UDP/HTTP/WebSocket）、序列化（Binary/XML/JSON）、APM性能追踪、对象容器、并行模型、定时调度、插件框架等。支持.NET Framework 4.5至.NET 11全版本。

DH.NIoT by: 湖北登灏科技有限公司

IoT Standard Library — defines unified communication protocol contracts for IoT platforms and hardware drivers. No concrete protocol implementations. Async-first IDriver with structured results: ReadResult (Quality/Timestamp), WriteResult (zero-allocation struct), ControlResult. ThingSpec thing model for properties/events/services. ITransport unifies serial/TCP/UDP/HTTP transport. | IoT标准库，为物联网平台与硬件驱动定义统一通信协议契约，不含具体协议实现。异步优先IDriver配合结构化结果。ThingSpec物模型。ITransport统一传输层。

DH.NIP by: 湖北登灏科技有限公司

高性能本地IPv4归属地查询库，基于MMF二分检索并支持IP库自动更新。

DH.NRedis by: 湖北登灏科技有限公司

性能Redis客户端，支持RESP2/RESP3协议，覆盖Redis 2.8～7.x全部数据结构与命令，内置消息队列（简单/可靠/延迟/Stream），支持集群/哨兵/云厂商适配，经日均80+亿次调用验证

DH.NRemoting by: 湖北登灏科技有限公司

提供RPC、HTTP、WebSocket与SRMP统一通信能力

DH.NStardust by: 湖北登灏科技有限公司

星尘分布式服务框架核心库。提供配置中心、注册中心、服务发现、全链路追踪、APM性能监控、日志中心等客户端SDK，支持配置拉取、服务注册与发现、调用追踪、性能和日志上报。

diskann-garnet by: Microsoft

DiskANN FFI and Data Provider for Garnet

DnsClient by: MichaCo

DnsClient.NET is a simple yet very powerful and high performance open source library for the .NET Framework to do DNS lookups

DynamicData by: Roland Pheasant

Bring the power of Rx to collections using Dynamic Data. Dynamic Data is a comprehensive caching and data manipulation solution which introduces domain centric observable collections. Linq extensions enable dynamic filtering, sorting, grouping, transforms, binding, pagination, data virtualisation, expiration, disposal management plus more.

DynamicExpresso.Core by: Davide Icardi

C# expression interpreter/evaluator

Elasticsearch.Net by: Elastic and contributors

Elasticsearch.Net

EMGU.CV by: Emgu Corporation

Emgu CV is a cross platform .Net wrapper to the OpenCV image processing library. Allowing OpenCV functions to be called from .NET compatible languages such as C#, VB, VC++, IronPython etc.

EntityFramework by: Microsoft

Entity Framework 6 (EF6) is a tried and tested object-relational mapper for .NET with many years of feature development and stabilization.

Enums.NET by: Tyler Brinkley

Enums.NET is a high-performance type-safe .NET enum utility library

EnyimMemcachedCore by: cnblogs.com

EnyimMemcachedCore is .NET Core client library for memcached. Usage: services.AddEnyimMemcached(options => options.AddServer(serverNameOrIP, 11211)); Then add IMemcachedClient into constructor. Use app.UseEnyimMemcached() to warm up.

EPPlus.Core by: Vahid Nasiri

EPPlus.Core is an unofficial port of the EPPlus library to .NET Core.