LLBLGen Pro is described as 'generates a complete data-access tier and business objects tier for multiple target frameworks (in C# or VB.NET*), utilizing powerful O/R mapping technology and a flexible task-based code generator, allowing you to at least double your productivity!'. There are three alternatives to LLBLGen Pro for Windows and .NET Framework. The best alternative is LinqConnect Professional. It's not free, so if you're looking for a free alternative, you could try Entity Developer or MyGeneration.
LinqConnect is a LINQ to SQL compatible ORM solution with extended functionality, support for SQL Server, Oracle, MySQL, PostgreSQL, and SQLite, its own visual model designer, seamlessly integrating to Visual Studio, and SQL monitoring tool.
Entity Developer is a powerful ORM designer for ADO.NET Entity Framework, NHibernate, LinqConnect, Telerik Data Access, and LINQ to SQL. You can use Model-First and Database-First approaches to design your ORM model and generate C# or Visual Basic .NET code for it.
MyGeneration is an extremely flexible template based code generator written in Microsoft.NET. MyGeneration is great at generating code for ORM architectures. The meta-data from your database is made available to the templates through the MyMeta API.