Hyperledger Composer is a complete set of business tools for creating enterprise blockchain applications. Developed as part of the Hyperledger project, Composer was created to simplify the development of open-source blockchain applications. It makes it easier for organizations and business networks to develop collaborative blockchain applications for different use cases.

Composer has five key components: rapid application development framework, application runtime, model-driven programming languages, comprehensive APIs, and a comprehensive set of tools to set up and manage applications. The application runtime feature allows developers to create their own distributed ledger, develop smart contracts and define transactions. The model-driven programming language feature consists of the Composer model language and CTO-scripting language, which allow developers to quickly create smart contracts tailored to their needs.

The comprehensive APIs feature provides developers with quick access to existing resources and components, reducing development time and effort. Finally, the tools to set up and manage applications make it easier for users to quickly set up, test and deploy applications, without needing extensive coding know-how.

When the Hyperledger Composer was first released, it was met with enthusiasm from developers looking to unlock the potential of the distributed ledger technology. However, work on Composer has since been absorbed into the more comprehensive Hyperledger Fabric platform. This move by Hyperledger provides users with an enhanced, scalable and more secure platform for developing blockchain applications.

Today, Hyperledger Composer's best feature is that it makes it easier for users to develop secure and fast blockchain applications. It provides developers with a model-driven programming language for quick and easy development, comprehensive APIs for quickly accessing existing components, and tools for quickly setting up and managing applications. With the integration into Hyperledger Fabric, it is now part of an even more comprehensive platform for distributed ledger applications, giving developers an even wider range of features and capabilities.