Top 20 NuGet ORM Packages

A high performance Micro-ORM supporting SQL Server, MySQL, Sqlite, SqlCE, Firebird etc..
LINQ to DB is a data access technology that provides a run-time infrastructure for managing relational data as objects.
T4 templates to generate data models for LINQ to DB SQL
PetaPoco is a tiny, single file .NET data access layer inspired by Massive that works with both non-dynamic POCO objects and dynamics. This package includes the core PetaPoco library + T4 templates to generate POCO classes from your database
Shared design-time components for Entity Framework Core tools.
The Dapper SqlBuilder component, for building SQL queries dynamically.
Light, simple and fast convention-based code-first POCO ORM for Sql Server. Support for Creating and Dropping Table Schemas from POCOs, Complex Property types transparently stored in schemaless text blobs in SQLServer.
.NET utility library that includes Application Configuration, lightweight ADO.NET Data Access Layer, logging, utility classes include: StringUtils, ReflectionUtils, FileUtils, DataUtils, SerializationUtils, TimeUtils, SecurityUtils and XmlUtils. These classes are useful in any kind of .NET project.
Fluent, XML-less, compile safe, automated, convention-based mappings for NHibernate.
In-memory database provider for Entity Framework Core (to be used for testing purposes).
Shared Entity Framework Core components for relational database providers.
Shared test suite for Entity Framework Core relational database providers.
SQLite database provider for Entity Framework Core.
Microsoft SQL Server database provider for Entity Framework Core.
Entity Framework Core Tools for the NuGet Package Manager Console in Visual Studio. Enables these commonly used commands: Add-Migration Drop-Database Get-DbContext Scaffold-DbContext Script-Migrations Update-Database
SQLite database provider for Entity Framework Core.
A library which is able to decompile a delegate or a method body to its lambda representation
DbExtensions is a data-access framework with a strong focus on query composition, granularity and code aesthetics. It supports both POCO and dynamic (untyped) mapping.
SQLite-Net Extensions is a very simple ORM that provides cascade operations, one-to-one, one-to-many, many-to-one, many-to-many, inverse and text-blobbed relationships on top of the sqlite-net library.
The SQLServer, ODBC, and OLEDB providers for Insight.Database. These are automatically included in the Insight.Database package, except the ODBC provider for .NET Core 2.0, which is in Insight.Database.Providers.Odbc.