The need to enhance the access of developing countries, within the UNFCCC process, to information on state-of-the-art environmentally sound technologies (ESTs) has been recognized since the first Conference of the Parties (COP). Decision 13/CP.1 on the transfer of technology requested the Convention secretariat "to prepare an inventory and assessment of environmentally sound and economically viable technologies and know-how conducive to mitigating and adapting to climate change. This inventory should also include an elaboration of the terms under which transfers of such technologies and know-how could take place".

The databases of TT:CLEAR was implemented to provide a comprehensive and consistent set of information for different technologies. Such a set of data is broad and complex and includes a number of data already compiled and stored in existing databases. Therefore, the TT:CLEAR databases were designed in a modular fashion. These databases include:

- Technology transfer projects (TTProjects) storing data on projects under implementation or proposed for implementation.
- Environmental Sound technologies (ESTs) containing generic data on technical, economic, and emissions parameters of different technologies.
- Contacts, Organization and Links containing contact information of relevant experts, organization and web sites.