# KnockKnock > security software for macOS **Wikidata**: [Q125475015](https://www.wikidata.org/wiki/Q125475015) **Source**: https://4ort.xyz/entity/knockknock ## Summary KnockKnock is free, open-source security software designed for macOS. Developed by the non-profit organization Objective-See, it helps users identify persistently installed software on their Apple computers. ## Key Facts - KnockKnock is security software for macOS, designed to identify persistently installed software. - It is developed by Objective-See, a non-profit software organization founded in 2015. - KnockKnock is distributed under the GNU General Public License, version 3.0. - The software runs on macOS, an operating system for Apple computers first released on March 24, 2001. - It is programmed using Objective-C, a high-level, object-oriented programming language that originated in 1984. - The latest stable version provided is 3.1.0, released on January 5, 2025. - KnockKnock is categorized as both computer security software and free software. - Its source code is publicly available on GitHub. ## FAQs ### Q: What is KnockKnock? A: KnockKnock is free security software specifically designed for macOS. It helps users detect and identify persistently installed software on their Apple computers, enhancing system security. ### Q: Who developed KnockKnock? A: KnockKnock was developed by Objective-See, a non-profit software organization. Objective-See was founded in 2015 and is headquartered in Kula, United States. ### Q: What operating system does KnockKnock run on? A: KnockKnock runs exclusively on macOS, the operating system developed by Apple for its computers. macOS was first released on March 24, 2001. ### Q: Is KnockKnock free to use? A: Yes, KnockKnock is free software. It is distributed under the GNU General Public License, version 3.0, allowing users to freely run, study, change, and distribute it. ### Q: What programming language is KnockKnock written in? A: KnockKnock is written in Objective-C, a general-purpose, high-level, object-oriented programming language that originated in 1984. ## Why It Matters KnockKnock plays a crucial role in enhancing the security posture of macOS systems by providing users with transparency into their installed software. In an era where persistent malware and unwanted programs can silently embed themselves within an operating system, KnockKnock offers a vital tool for detection. By identifying all persistently installed software, it empowers users to scrutinize these components, determine their legitimacy, and remove anything suspicious. This capability is particularly significant for macOS, which, despite its reputation for security, is not immune to threats. As free and open-source software, KnockKnock lowers the barrier to entry for advanced security analysis, making sophisticated tools accessible to a broader audience. Its development by a non-profit organization further underscores its commitment to user security over commercial interests, fostering trust and community engagement in cybersecurity efforts. ## Notable For - Being free and open-source security software specifically for macOS. - Its development by Objective-See, a non-profit organization focused on macOS security tools. - Providing users with the ability to identify all persistently installed software on their macOS systems. - Being licensed under the GNU General Public License, version 3.0. ## Body ### Overview KnockKnock is a security software application designed for the macOS operating system. Its primary function is to identify and list all persistently installed software components on an Apple computer. This includes applications, daemons, launch agents, and other items that are configured to run automatically or maintain a presence on the system. ### Development and Licensing KnockKnock is developed by Objective-See, a non-profit software organization. Objective-See was established in 2015 and is headquartered in Kula, United States. The software is categorized as free software and computer security software. It is distributed under the terms of the GNU General Public License, version 3.0, which permits users to freely run, study, change, and distribute the software and its modified versions. The copyright status of KnockKnock is copyrighted. ### Technical Specifications KnockKnock is programmed using Objective-C, a general-purpose, high-level, object-oriented programming language that originated in 1984. It operates exclusively on macOS, the operating system for Apple computers, which was first released on March 24, 2001. The software is also known by the alias "Knock Knock". ### Version History KnockKnock has undergone several stable releases, with the latest provided version being 3.1.0. - Version 2.2.0 was released on February 26, 2021. - Version 2.2.1 was released on February 27, 2021. - Version 2.3.0 was released on March 4, 2021. - Version 2.4.0 was released on June 27, 2023. - Version 2.4.1 was released on July 3, 2023. - Version 2.4.2 was released on July 7, 2023. - Version 2.5.0 was released on September 29, 2023. - Version 3.0.0 was released on December 1, 2024. - Version 3.0.1 was released on December 12, 2024. - Version 3.1.0 was released on January 5, 2025. ### Availability The official website for KnockKnock is objective-see.org/products/knockknock.html, which is available in English. The source code for KnockKnock is publicly hosted on GitHub at https://github.com/objective-see/KnockKnock. ## References 1. [Source](https://github.com/objective-see/KnockKnock/blob/main/LICENSE) 2. [Release 2.2.0. 2021](https://github.com/objective-see/KnockKnock/releases/tag/v2.2.0) 3. [Release 2.2.1. 2021](https://github.com/objective-see/KnockKnock/releases/tag/v2.2.1) 4. [Release 2.3.0. 2021](https://github.com/objective-see/KnockKnock/releases/tag/v2.3.0) 5. [Release 2.4.0. 2023](https://github.com/objective-see/KnockKnock/releases/tag/v2.4.0) 6. [Release 2.4.1. 2023](https://github.com/objective-see/KnockKnock/releases/tag/v2.4.1) 7. [Release 2.4.2. 2023](https://github.com/objective-see/KnockKnock/releases/tag/v2.4.2) 8. [Release 2.5.0. 2023](https://github.com/objective-see/KnockKnock/releases/tag/v2.5.0) 9. [Release 3.0.0. 2024](https://github.com/objective-see/KnockKnock/releases/tag/v3.0.0) 10. [Release 3.0.1. 2024](https://github.com/objective-see/KnockKnock/releases/tag/v3.0.1) 11. [Release 3.1.0. 2025](https://github.com/objective-see/KnockKnock/releases/tag/v3.1.0) 12. [Release 4.0.0. 2025](https://github.com/objective-see/KnockKnock/releases/tag/v4.0.0) 13. [Release 4.0.1. 2025](https://github.com/objective-see/KnockKnock/releases/tag/v4.0.1) 14. [Release 4.0.2. 2025](https://github.com/objective-see/KnockKnock/releases/tag/v4.0.2) 15. [Release 4.0.3. 2025](https://github.com/objective-see/KnockKnock/releases/tag/v4.0.3)