# Ξ Project:M36 Relational Algebra Engine [](https://www.haskell.org) [](http://unlicense.org) [](http://hackage.haskell.org/package/project-m36) [](http://packdeps.haskellers.com/feed?needle=project-m36) [](https://travis-ci.org/agentm/project-m36) *Software can always be made faster, but rarely can it be made more correct.* ## Introduction Project:M36 implements a relational algebra engine as inspired by the writings of Chris Date. ## Description Unlike most database management systems (DBMS), Project:M36 is opinionated software which adheres strictly to the mathematics of the relational algebra. The purpose of this adherence is to prove that software which implements mathematically-sound design principles reaps benefits in the form of code clarity, consistency, performance, and future-proofing. Project:M36 can be used as an in-process or remote DBMS. Project:M36 is written entirely in the [Haskell programming language](https://www.haskell.org/). ## Sample Session [](https://asciinema.org/a/3syu35c8cydm403292a74l1n5) ## Try It! You can experiment instantly with Project:M36 straight from your browser at [try.project-m36.io](https://try.project-m36.io)! ## Use-Cases Project:M36 supports multiple frontends which target different audiences. * learn about the relational algebra via TutorialD * store and manipulate databases * use Project:M36 as a native Haskell database backend ## Community * [Developer's Blog](https://agentm.github.io/project-m36/) * [Mailing List/Discussion Group](https://groups.google.com/d/forum/project-m36) * IRC Channel: chat.freenode.net #project-m36 * [Hackage](https://hackage.haskell.org/package/project-m36) ## Documentation ### Introductory Materials 1. [Installation and Introduction to Project:M36](docs/introduction_to_projectm36.markdown) 1. [Introduction to the Relational Algebra](docs/introduction_to_the_relational_algebra.markdown) 1. [TutorialD Tutorial](docs/tutd_tutorial.markdown) 1. [15 Minute Tutorial](docs/15_minute_tutorial.markdown) 1. [Developer's Change Log](Changelog.markdown) ### Database Comparisons 1. [ACID Database Properties](docs/acid_assessment.markdown) 1. [On NULL (in SQL)](docs/on_null.markdown) 1. [Reaching "Out of the Tarpit" with Project:M36](docs/reaching_out_of_the_tarpit.markdown) ### Advanced Features 1. [Transaction Graph Operators](docs/transaction_graph_operators.markdown) 1. [ProjectM36.Client Library](docs/projectm36_client_library.markdown) 1. [Adding New Data Types](docs/new_datatypes.markdown) 1. [Database-Manipulating Functions](docs/database_context_functions.markdown) 1. [Serving Remote ProjectM36 Databases](docs/server_mode.markdown) 1. [Using Notifications](docs/using_notifications.markdown) 1. [Merge Transactions](docs/merge_transactions.markdown) 1. [WebSocket Server](docs/websocket_server.markdown) 1. [Atom (Value) Functions](docs/atomfunctions.markdown) 1. [Trans-Graph Relational Expressions](docs/transgraphrelationalexpr.markdown) 1. [Isomorphic Schemas](docs/isomorphic_schemas.markdown) 1. [Replication](docs/replication.markdown) ## Development Project:M36 is developed in Haskell and compiled with GHC 7.10 or GHC 8.0.2 or later. ## Related Projects * [The Third Manifesto](http://thethirdmanifesto.com/): the philosophical basis for relational algebra engines * [Rel](http://reldb.org/): a TutorialD implementation against a BerkeleyDB backend * [Andl](http://andl.org/): a new database language with SQLite and PostgreSQL backends * [Coddie](https://github.com/scvalencia/Coddie): a python-based relational algebra interpreter ## Suggested Reading * [Out of the Tarpit](http://shaffner.us/cs/papers/tarpit.pdf): a proposed software architecture which minimizes state and complexity. Project:M36 implements the requirements of this paper. * [Database Design & Relational Theory: Normal Forms and All That Jazz](http://shop.oreilly.com/product/0636920025276.do): mathematical foundations for the principles of the relational algebra * [Database Explorations: Essays on the Third Manifesto and Related Topics](http://bookstore.trafford.com/Products/SKU-000177853/Database-Explorations.aspx): additional essays and debates on practical approaches to relational algebra engine design