From the commercial trade exchange (“barter”) sector, there are several software platforms now available. Two that I’ve seen that have a good user interface and a high level of functionality are :
GETS, developed by Richard Logie of Scotland.
GETS is used to power his own trade exchange, The Business Exchange http://www.4xuk.com/, as well as the Universal Currency (UC) system, which enables trade exchanges to trade with one another. The UC website is at http://www.ucci.biz/.
XO is a software company in New Zealand that has developed a very powerful,
fully featured package. http://www.barter-software.com/en/home/index.aspx.
Here is a description taken from their website:
The XO software has a complete online marketplace which allows your members to list their products and services online. It also provides them with the opportunity to make purchases from other members, with the funds instantly debited from their account, thereby saving paperwork.