Feathers vs. Meteor
Feathers is community supported, whereas Meteor is venture backed and has raised $31.2 million to date.
Meteor only has official support for MongoDB but there are some community modules of various levels of quality that support other databases. Meteor has it's own package manager and package ecosystem. They have their own template engine called Blaze which is based off of Mustache along with their own build system, but also have guides for Angular and React.
Feathers has official support for many more databases and supports any front-end framework or view engine that you want. We have framework guides for integrating Feathers with many of the most popular.
Meteor has optimistic UI rendering and oplog tailing whereas currently Feathers leaves that up to the developer. However, we've found that being universal and utilizing websockets for both sending and receiving data alleviates the need for optimistic UI rendering and complex data diffing in most cases.
Both Meteor and Feathers provide support for email/password and OAuth authentication. Once authenticated Meteor uses sessions to maintain a logged in state, whereas Feathers keeps things stateless and uses JSON Web Tokens (JWT) to assess authentication state.
One big distinction is how Feathers and Meteor provide real-time across a cluster of apps. Feathers does it at the service layer or using another pub-sub service like Redis whereas Meteor relies on having access to and monitoring MongoDB operation logs as the central hub for real-time communication.