My .NET components:

• Pivot Table Data library for .NET - in-memory data cube, OLAP operations, pivot table model, web pivot tables & pivot charts builder
• NLQuery - natural language query parser for search-driven interfaces
• PDF Generator for .NET (wkhtmltopdf wrapper) - HTML-to-PDF converter
• VideoConverter for .NET (FFMpeg wrapper) - convert video files, extract thumbnails, encode video from images etc
• Recommendation Engine for .NET - C# port of Apache Mahout Collaborative Filtering framework
• and others: NReco website

I'm maintainer of the following open-source projects:

• NReco.Data - lightweight DB-independent DAL (micro-ORM): abstract dynamic queries, SQL commands generation, POCO mapping
• NReco.LambdaParser - parser and evaluator for formulas and lambda-expressions
• NReco.Logging.File - simple file logging provider for MVC Core

Other projects:

• SeekTable.com - free online BI tool (pivot table and pivot charts builder)
• PivotData microservice - lightweight ROLAP server that provides web API for pivot tables and pivot charts generation by SQL database, MongoDb, CSV files. Includes web pivot builder that can be integrated into any web application.