1. LUCENE.NET Lucene.Net is a port of the Lucene search engine library, written in C# and targeted at .NET runtime users. The Lucene search library is based on an inverted index. Lucene.Net has three primary goals: Maintain the existing line-by-line port from Java to C#, fully automating and commoditizing the process such that the project can easily synchronize with the Java Lucene release sched..