Kotlin-based Spek uses standard lambdas for defining specs, whereas Spock digs into the Apache Groovy parser to change the meaning of labels in the syntax, as w

Kotlin-based Spek uses standard lambdas for defining specs, whereas Spock digs into the Apache Groovy parser to change the meaning of labels in the syntax, as well as uses operator overloading. One's elegantly functional, the other's a cheap hack.