Signal Messenger

Signal is a cross-platform, privacy-focused encrypted messaging service developed by the Signal Technology Foundation and Signal Messenger, LLC. The product's history is deeply rooted in the work of cryptographer Moxie Marlinspike, who initially launched predecessors such as TextSecure and RedPhone under the startup Whisper Systems in 2010. After a brief acquisition by Twitter in 2011, the projects were transitioned back to an open-source model under the banner of Open Whisper Systems in 2013, which officially merged the voice and text applications into Signal in 2014.

In 2018, Brian Acton, the co-founder of WhatsApp, left Facebook and invested $50 million to establish the Signal Technology Foundation alongside Marlinspike. This non-profit structure was specifically designed to ensure the application remains independent of corporate profit motives and advertiser influence. Today, Signal is headquartered in Mountain View, California, and is governed by a 501(c)(3) non-profit status, making it one of the few global communication platforms not controlled by a traditional for-profit corporation.