Extempore is a systems programming language designed to support the programming of real-time systems in real-time. Extempore promotes human orchestration as a meta model of real-time man-machine interaction in an increasingly distributed and environmentally aware computing context.

Extempore is designed to support a style of programming dubbed 'cyberphysical' programming. Cyberphysical programming supports the notion of a human programmer operating as an active agent in a real-time distributed network of environmentally aware systems. The programmer interacts with the distributed real-time system procedurally by modifying code on-the-fly. In order to achieve this level of on-the-fly interaction Extempore is designed from the ground up to support code hot-swapping across a distributed heterogeneous network, compiler as service, real-time task scheduling and a first class semantics for time.

Extempore is designed to mix the high-level expressiveness of Lisp with the low-level expressiveness of C. Extempore is a statically typed, type-inferencing language with strong temporal semantics and a flexible concurrency architecture in a completely hot-swappable runtime environment. Extempore makes extensive use of the LLVM project to provide back-end code generation across a variety of architectures.

For more detail on what the Extempore project is all about, see the Extempore philosophy.

To see Extempore in action, check out these videos:

• interactive, distributed, physics simulation
• graphics demo
• general introduction
• a more technical intro

Installation

OSX

If you're a homebrew user, it's pretty straightforward:

brew tap benswift/extempore
brew install extempore

If you get stuck, there are more detailed instructions here.

Alternately, you can build it yourself from source.

Linux

On Linux, too, you can build Extempore through homebrew or build from source.

Windows 7

Windows installation instructions are available here.

Extempore has thus far only been tested on Windows 7 64-bit, but if you can get it to build/run on other flavours of Windows then do let us know and we'll update these instructions. Also, if anyone wants to improve and streamline the Windows build process, then patches are welcome :)

Running Extempore

You don't need to do anything special to run extempore, it'll just run in any terminal (or command prompt on Windows).

$ ./extempore

The running extempore process acts as a server, and you send extempore code to the server for evaluation (by default on port 7099).Once you've started extempore you can connect using either telnet, Emacs, vim, Sublime Text, or whatever you like. The Emacs support is probably the most mature at the moment, but patches are welcome for other editors.

There are some optional command line options that you may want to use you can get a list by running ./extempore --help

For more detail, see this post on interacting with the Exempore compiler.

Docs & Community

More Extempore documentation can be found at http://benswift.me/extempore-docs/index.html

You can also join the Extempore community:

• Extempore google group
• Extempore mailing list

Licence

Copyright (c) 2011-2014, Andrew Sorensen

All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

Neither the name of the authors nor other contributors may be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.