The CORE.gov site is meant to provide a centralized collaboration environment for the development and sharing of government software and application components. It provides a method for registration and reuse.
CORE.GOV grew out of the Federal Enterprise Architecture (FEA) Project Management Office, the goal of which is to support cross-agency collaboration, transformation and government-wide improvement. CORE.GOV offers an environment where component developers and reusers collaborate seamlessly and easily. 
At Core.gov, participants can:
- Search for and locate a specific component that meets a government agency's needs
- Find components that can be customized to meet a department's unique requirements
- Recommend components for inclusion in CORE.GOV.
CORE.gov began operation in March 2004. Over time, it will become a networked community of component developers and reusers and will offer numerous components of various types and complexities, including business components, e-forms and technical components.
Importance of the CORE.gov Effort
With the growing influence of the Federal Enterprise Architecture initiative, agencies are under pressure to standardize their operations and their applications. As they move toward standardization, there is an increased likelihood that certain application components can (potentially) be reused by other agencies and other applications. At this time, only a small percentage of applications are being reused, but this has the potential to increase in the years ahead. CORE.gov helps coordinate the component-sharing effort.
 Details come from the core.gov Web site