Ambient-Oriented programming is a paradigm geared towards mobile computing. Mobile hardware (such as cell phones) is mostly equipped with wireless networking, allowing it to collaborate with nearby devices in its environment. However, because wireless network links are volatile (basically: when devices move out of wireless range, the connection drops), network failures occur much more frequently than in traditional networks. The basic assumption of the Ambient-Oriented Programming paradigm is that languages should incorporate network failures at the heart of their programming model, and not treat them as “exceptions”.

Our own experimental language, AmbientTalk, differs from most traditional languages because:

• It employs a purely event-driven concurrency framework, founded on actors.
• It abandons the RPC abstraction in favor of asynchronous, non-blocking message passing. Because the system automatically buffers such messages while the receiver of the message is disconnected, the programmer can make abstraction from temporary network failures by default.
• It has built-in programming language constructs for objects to discover one another in the local ad hoc network. Peer-to-peer service discovery is built into the language.
• It features a dynamic OO kernel language built upon the principles of prototype-based programming (based on Scheme, Self and Smalltalk). The kernel language supports reflection using mirrors, which provide access to an extensive metaobject protocol, making the language extensible from within itself.
• The language syntax derives primarily from the 'curly brace' family of languages, but it mixes in the keyworded messaging syntax from Smalltalk as well. This, together with AmbientTalk's lightweight block syntax, enables you to easily build your own control structures. Like many other dynamic and functional languages, AmbientTalk embraces the use of blocks to express higher-order, functional patterns.
• The current implementation of AmbientTalk embraces the JVM as a platform. It's easy for AmbientTalk programs to use Java libraries, and it's easy for Java objects to use !AmbientTalk as an embedded scripting language. This interaction is safe: even when AmbientTalk objects are “exposed” to the JVM, JVM threads cannot violate the concurrency constraints of AmbientTalk's actor model.

Check out the introduction to AmbientTalk for a hands-on example showing you the benefits in actual code. Alternatively, glance at the key expressions in the language to get a 60-second overview of the language's design and intents.

The screencast below shows how to implement a simple echo server for mobile ad hoc networks. It introduces AmbientTalk's support for peer-to-peer service discovery, asynchronous messages, futures and how remote object references are resilient to network failures by default:

AmbientTalk is not our only research artifact. We have ported the ideas of Ambient-oriented Programming to Scheme, leading to the iScheme language. There is also CRIME, a data-driven programming language which explores the logic programming paradigm to tackle similar coordination issues in mobile ad hoc networks.

AmbientTalk's mirages have inspired the development of proxies in ECMAScript harmony.

The AmbientTalk mailing list, for questions and general information on AmbientTalk: . If you want to contact any one of us personally, please see the People pages for personal contact details.

If you're interested in the Ambient-oriented Programming paradigm in general, check out the papers on AmOP page. The seminal OOPSLA2005 Onward! paper pretty much sums up our earliest musings on AmOP.

If you're interested in the AmbientTalk programming language, check out the papers on AmbientTalk page. The ECOOP2006 paper is the first paper describing AmbientTalk in-depth. However, in mid 2006 the language was extensively revised giving rise to AmbientTalk/2. While both languages have an actor-based model of concurrency and feature abstractions for service discovery, AmbientTalk/2 features event loop concurrency model and a more modular and stratified meta-level programming abstractions.

Since 2007 AmbientTalk refers to AmbientTalk/2 and Dedecker's original AmbientTalk is no longer in use. A good starting point for reading about the current AmbientTalk language is the SCCC2007 paper.

AmbientTalk is actively used as a research tool: it is extended with new language features, either dedicated to further facilitate the development of software for ad hoc networks, or to explore the suitability of the language in new domains. Check out the research page for more information.