Eliom's Homepage

Eliom is a framework for programming web sites and client/server web applications. It uses very new concepts making programming very different from all other web programming tools, and allowing to write a complex web site in very few lines of code. Both server and client parts of the program are written in OCaml, as a single program.

Eliom 4.0


A few weeks after Js_of_ocaml 2, we are happy to announce release 4.0 of Eliom. Eliom is a framework for writing Web sites and client-server Web applications in OCaml. It can be used to build simple Web sites as well as complex Web applications. In the latter case, both client and server parts are written in OCaml, as a single program, with a syntax to distinguish both parts. Thus, communication between server and client is very easy.

This release brings the following new features:

A lot of efforts have been put in documentation improvements. The full Changelog is available here: https://ocsigen.org/eliom/changelog

Migration from 3.0 should be very easy: https://ocsigen.org/eliom/Eliom40

If you want to start learning Eliom, the best starting point is the tutorials on page https://ocsigen.org/tuto/manual/ even when you are an advanced OCaml programmer. Choose the tutorial that best fits your needs.

This release is the result of a collaboration with Besport inc. We send them our warm acknowledgements for their contributions, especially to Hugo Heuzard. We also thank Guillem Rieu, from Domoco, for his contributions.

Eliom is a collaborative work by the Ocsigen team.

Vincent Balat, for the Ocsigen team



  • Integrated client and server side programming with automatic bidirectional communication
  • Mixes traditional Web interaction with very dynamic client side features
  • Dynamic creation of services
  • Static checking of HTML
  • Automatic management of sessions
  • Concise and modular programming

Other projects

Read also the Ocsigen tutorial ...