Widely used

Roaring is found in Apache Lucene and derivative systems such as Solr and Elastic, Metamarkets’ Druid, Apache Spark, Whoosh, eBay’s Apache Kylin.

Portable

There are freely available software libraries providing Roaring bitmaps in almost all the popular programming languages (Java, C, C++, Go, C#, Rust, Python…). There is a serialized format specification for interoperability between implementations.