From Gentoo Wiki
Erlang is a concurrent, functional language, adapted to writing distributed, fault tolerant systems.
USE flags for dev-lang/erlang Erlang programming language, runtime environment and libraries (OTP)
||Add extra documentation (API, Javadoc, etc). It is recommended to enable per package instead of globally|
||Add support for GNU Emacs|
||Add support for Java|
||Enable kernel polling support|
||Add ODBC Support (Open DataBase Connectivity)|
||Support for Stream Control Transmission Protocol|
||Add support for SSL/TLS connections (Secure Socket Layer / Transport Layer Security)|
||Enable use of systemd-specific libraries and features like socket activation or session tracking|
||Add support for Tk GUI toolkit|
||Add support for wxWidgets/wxGTK GUI toolkit|
emerge --ask dev-lang/erlang
Erlang/OTP 24 [erts-12.0.2] [source] [64-bit] [smp:12:12] [ds:12:12:10] [async-threads:1] [jit] Eshell V12.0.2 (abort with ^G) 1>
To exit the shell: Ctrl+g then q and Return.