 Opa implements strong, static typing, which can be helpful in protecting against security issues such as SQL injections and cross-site scripting attacks.The language was first officially presented at the OWASP conference in 2010, and the source code was released on
GitHub
in June 2011, under a GNU Affero General Public License.Later, the license changed to the MIT license for the framework part (library) and AGPL for the compiler so that applications written in Opa can be released under any license, proprietary or open source.