OLI-it allows users to post messages online to make general or specific requests for information, goods, or services. Other logged-in users may then reply to the posted messages. All queries are publicly visible. OLI-it provides a collection of SOAP-based APIs that enable users to access the website's functions programmatically.
The website is offered primarily in German, though parts of it (not including API documentation) are available in English and Spanish as well. Most of the queries have been written in German.