[Caml-list] Eliom 6.0: mobile and Web apps in OCaml

[Vasilis Papavasileiou <ocsigen@vasilis.airpost.net>]

We are very happy to announce the release of Ocsigen Eliom 6.0 [1],
which follows the recent releases of Ocsigen Server 2.8 [2] and
Ocsigen Js_of_ocaml 2.8.x [3].

New features include a friendlier service API that retains the
expressive power of our service system. Additionally, Eliom can now be
used to build cross-platform Web/mobile applications (Android, iOS,
...).

## What is Eliom?

Eliom is a framework for developing client/server web
applications. Both the server and the client parts of the application
are written in OCaml, as a single program. Communication between
server and client is straightforward, e.g., one can just call a
server-side function from client-side code.

Eliom makes extensive use of the OCaml language features. It provides
advanced functionality like a powerful session mechanism and support
for functional reactive Web pages.

## Friendly service APIs

Services are a key concept in Eliom, used for building the pages that
are sent to the user, for accessing server-side data, for performing
various actions, and so on. Eliom 6.0 provides a friendlier API for
defining and registering services, thus making Eliom more
approachable.

The new API makes extensive use of OCaml's GADTs, and provides a
single entry-point that supports most kinds of services
(`Eliom_service.create`). For more information, refer to the
Eliom manual [4].

## Mobile applications

Eliom 6.0 allows one to build applications for multiple mobile
platforms (including iOS, Android, and Windows) with the same codebase
as for a Web application, and following standard Eliom idioms.

To achieve this, we have made available the Eliom service APIs on the
client [5]. Thus, the user interface can be produced directly on the
mobile device, with remote calls only when absolutely necessary.

To build an Eliom 6.0 mobile application easily, we recommend that you
use our Ocsigen Start [6] project, which provides a mobile-ready
template application. Ocsigen Start is currently available in OPAM as
a preview, with an 1.0 release coming soon.

## Compatibility

Eliom 6.0 supports the last 3 major versions of OCaml (4.02 up to
4.04). Additionally, Eliom is compatible with and builds on the latest
Ocsigen releases, including Ocsigen Server 2.8, Js_of_ocaml 2.8.x, and
TyXML 4.0.x.

## Future

The Ocsigen team is busy working on new features. Notably, we are
developing an OCaml compiler [7] specifically tuned for
Eliom. Additionally, we are planning a transition to the Cohttp
backend.

## Support

- Migration guide: https://ocsigen.org/eliom/Eliom60
- Issue tracker: https://github.com/ocsigen/eliom/issues
- Mailing list: https://sympa.inria.fr/sympa/info/ocsigen
- IRC: `#ocsigen` on `irc.freenode.net`

[1]: https://github.com/ocsigen/eliom/releases/tag/6.0.0
[2]: https://github.com/ocsigen/ocsigenserver/releases/tag/2.8
[3]: https://github.com/ocsigen/js_of_ocaml/releases/tag/2.8.3
[4]: https://ocsigen.org/eliom/dev/manual/server-services
[5]: https://ocsigen.org/eliom/manual/clientserver-services
[6]: https://github.com/ocsigen/ocsigen-start
[7]: https://github.com/ocsigen/ocaml-eliom