IntelliJ IDEA is a proprietary IDE made by JetBrains. It can be used for many programming languages and SDKs, including Java, Scala, Android, and web development. It supports many more languages and frameworks through plugins. While the full version of IDEA requires a subscription, a community edition (IDEA CE) exists which requires no subscription. IDEA CE is mostly useful for JVM-based languages.
The subscription version, IntelliJ IDEA Ultimate, is available through the AUR asAUR. Community Edition is available as AUR.