Apps with 'Query Engine' feature

Obsidian is a note-taking app that lets you create a personal knowledge graph with ease. It is designed for non-linear thinking and allows you to easily link your notes together wiki-style.

As easy to use as a word document or bulleted list, and as powerful for finding, collecting, and connecting related ideas as a graph database. Collaborate with others in real time, or store all your data locally.

Very fast SPARQL Engine, which can handle very large knowledge graphs, offers context-sensitive autocompletion for SPARQL queries, and allows combination with text search.

The almighty jq processor, wrapped in a graphical UI.

PowerLite PDO is a DBAL PDO Wrapper, a lightweight and powerful PHP library that provides an efficient way to interact with multiple types of databases.

Cycle ORM from Spiral Scout provides a clean and simplified approach to object-relational mapping in PHP, designed with the developer in mind.

Memozine is a diary and personal information manager application that enables you to record, organise and search through all the information that matters to you in your daily life.