KrakenD
KrakenD offers two different editions, KrakenD CE (Community Edition) and KrakenD EE (Enteprise Edition). The API Gateway engine of KrakenD, an open source project, has joined the Linux Foundation as Lura. KrakenD touts that it's built for performance. This API Gateway is often deployed as a backend-for-frontend or a façade aggregator on top of many different microservices.
KrakenD is primarily used as a stateless component in user infrastructure. There's no data store dependency required for most operations, which may simplify deployment and management.
Message transformation can be configured using the Martian DSL while message validation can benefit from Google's Common Expression Language (CEL).
KrakenD has a JSON-based file configuration with a Web-based editor in KrakenD Designer (CE) or KrakenD Studio (EE). Enterprise features include commercial support, KrakenD studio, and enterprise plugins.