What is Bitrix24?
Bitrix24 is a collaboration platform launched by Bitrix, Inc. in
2012. Since its release, over five million organizations worldwide chose it.
Bitrix24 provides a complete suite of social collaboration, communication and
business development tools for your team, including CRM, files sharing, time
management, e-commerce, and more. It is available in cloud and onpremise, on desktop and mobile devices.
On-Premise version of the platform comes with source code access so the organization can install it on their own server.
Also, you can create a free account here