The Language Bar is the core user interface for Text Services Framework.

The Text Services Framework is designed to offer advanced language and word processing features to applications.

It supports features such as multilingual support, keyboard drivers, handwriting recognition, speech recognition, as well as spell checking and other text and natural language processing functions.

In August 2019, Google Project Zero discovered and publicly exposed a critical security vulnerability in CTF that dated back to its first release in Windows XP.

The vulnerability, known as CVE-2019-1162, allows privilege escalation and security boundary traversal.