Flat Learning Curve Convention-over-configuration, sensible defaults, opinionated APIs, and the Groovy language combine to make Grails easy to learn for Java developers.

On top of Spring Boot Grails is built on top of Spring Boot and leverages Spring Boot's time-saving features, such as Spring-powered dependency injection.

Smooth Java Integration Grails seamlessly and transparently integrates and interoperates with Java, the JVM, and existing Java EE containers.

Groovy-Based Apache Groovy is a language for the Java platform designed to enhance developers' productivity. It is an optionally-typed and dynamic language but with static-typing and static compilation capabilities.

Seamless GORM Integration Grails seamlessly integrates with GORM, a data access toolkit that provides a rich set of APIs for accessing relational and non-relational data. GORM also includes implementations for Hibernate (SQL), MongoDB, Cassandra, and Neo4j.

REST APIs, REACT, ANGULAR With the use of application profiles, including React and Angular, Grails allows developers to build REST APIs or modern web applications with a JavaScript frontend.

Plugins Developers can build plugins that extend and enhance Grails, or they can access existing plugins published by a vibrant plugin community.

View Technologies Technologies such as GSP, JSON Views, and Markup Views help developers effortlessly generate HTML, JSON and XML.

Asynchronous Capabilities The async features of Grails aim to simplify concurrent programming. Grails' features include the concept of Promises, a unified event model, and the use of RxJava to write reactive logic.

Open Source Grails is an Open Source Apache 2 License project.

Domain-Specific Languages Grails relies on expressive domain-specific languages (DSLs) for validation, querying, markup rendering, and more.