Watch this webinar to discover new and updated Salesforce Platform features coming in the Spring '13 Release including:
Tooling API -- The Tooling API is now generally available and provides SOAP and REST interfaces that allow you to build custom development tools for Force.com applications.
Connect in Apex -- Connect in Apex is now available for Developer Preview in all Developer Edition organizations. Connect in Apex exposes Chatter API data as Apex objects.
Force.com Canvas Updates -- Force.com Canvas, which allows you to embed a 3rd party app within Salesforce that can recognize user context, has a few new updates including the ability to expose a Canvas app on a custom Visualforce page.
Connected Apps -- Connected Apps are now generally available for integration using Salesforce Identity and Data APIs.