Hello,

You can definitely develop your custom webparts. Please see detailed description on how to do that in our Developer's Guide: http://devnet.kentico.com/docs/devguide/developing_web_parts.htm

Please see also KB article about integrating third-party controls to Kentico CMS: http://devnet.kentico.com/Knowledge-Base/Web-parts---Controls/Integrating-3rd-party-components-in-Kentico-CMS.aspx

Best regards
Ondrej Vasil