IT-Harvest, an industry analyst firm, curates a complete database of all the IT security vendors in the world. In addition to resources available on this site, the entire list is published every year in Security Yearbook. The latest edition is Security Yearbook 2023, shipping in June, 2023. The companies are listed by name, country/state, and category.  Change in headcount for each vendor is presented.

Here is a great video introduction to the entire IT security industry from data pulled together in 2016 and presented on the RSA TV stage.  

2020 was the first time that anyone has compiled and published such a directory. It is an invaluable tool for:

Other researchers. Wall Street analysts, other industry analysts, investors, private equity, and strategic acquirers can use the list as a starting place for their understanding of the IT security industry as a whole as well as regional concentrations and specific sector opportunities.

Industry practitioners. CISOs and product decision makers have a plethora of means to determine what product to purchase. Often they start with the vendors on a Gartner Magic Quadrant as a short list. Or they send people to industry conferences to learn about product offerings, or to meet with their peers to determine the best solution fit. With a complete directory in their hands industry practitioners can learn about all the solutions in a category and may discover a better fit than they would through other channels.

Students. Security Yearbook 2022 includes a history of the IT security industry that provides a deep understanding of the evolution, growth, and future of the space. It draws on data derived from the directory to highlight growth trends and market sizes.

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