Sphinx vs Groonga: What are the differences?

Developers describe Sphinx as "Open source full text search server, designed from the ground up with performance, relevance (aka search quality), and integration simplicity in mind". Sphinx lets you either batch index and search data stored in an SQL database, NoSQL storage, or just files quickly and easily — or index and search data on the fly, working with Sphinx pretty much as with a database server. A variety of text processing features enable fine-tuning Sphinx for your particular application requirements, and a number of relevance functions ensures you can tweak search quality as well. On the other hand, Groonga is detailed as "* An open-source full-text search engine and column store*". It is an embeddable super fast full text search engine. It can be embedded into MySQL. Mroonga is a storage engine that is based on it.

Sphinx and Groonga can be primarily classified as "Search Engines" tools.

Some of the features offered by Sphinx are:

• Output formats: HTML (including Windows HTML Help), LaTeX (for printable PDF versions), ePub, Texinfo, manual pages, plain text
• Extensive cross-references: semantic markup and automatic links for functions, classes, citations, glossary terms and similar pieces of information
• Hierarchical structure: easy definition of a document tree, with automatic links to siblings, parents and children

On the other hand, Groonga provides the following key features:

• Storage Engine
• Fast
• Easy to use

Groonga is an open source tool with 542 GitHub stars and 109 GitHub forks. Here's a link to Groonga's open source repository on GitHub.