Restforce is a lightweight Ruby gem that wraps the Salesforce.com REST API. The gem comes well documented with code examples that cover most implementation procedures for accessing the REST API parameters.
Really Simple Systems, a cloud-based CRM provider, has announced the release of version 4 of their API. The update comes at the request of the developer community and adds new features, while increasing security. Improvements include the ability to control authentication at the user level.
Zootle, UK based hosted CRM provider, offers most of its features through the SalesSystemCRM API. From prospecting to order processing, the API allows developers to integrate an entire ecommerce solution with its existing website and apps. The SalesSystemCRM app suite already focused and tailored to budgets in the SME space. However, an API makes the CRM provider even more attractive to businesses strapped for IT resources.