In light of the recent RedHat acquisition, this article provides the list of all the top companies that were acquired by IBM. How successful did those purchases turn out to be? You can be the judge of that.
https://www.investopedia.com/news/top-companies-owned-ibm/
There are more than 100 acquisitions.
https://en.wikipedia.org/wiki/List_of_mergers_and_acquisitions_by_IBM
Can't think of any successes - unless you count the acquired employees who were eventually forced out of IBM and then had stellar careers.
We acquired several hundred companies, small (2 to 10 employees) to large (1000+ employees)
Transarc Corporation
In 1994, IBM purchased Pennsylvania-based software outfit Transarc Corporation, a five-year-old company which had popularized multiple file system software. Among other products, Transarc developed a distributed transaction processing monitor called Encina; IBM utilized this product to develop its own UNIX-based products later on.
Lotus Software
The maker of the popular Lotus 1-2-3 spreadsheet application, one of the first user-friendly and accessible applications in the earliest days of IBM personal computers, Lotus Software was purchased by IBM in 1995 for the price of $3.5 billion. A major impetus for the acquisition was Lotus Notes, a popular application Lotus had developed prior to the purchase. IBM also bought the company as a means of accessing the client-server computing world, which threatened to make host-based software a thing of the past.
Rational Machines
In 2003, IBM bought and rebranded Rational Machines for the price of $2.1 billion. Rational provided an integrated development environment designed to enhance productivity in development team settings. IBM chose to purchase the company after the dot-com bubble burst and when Rational had declined in value (although the company was still highly profitable at the time).
Cognos
IBM investors and customers will likely have encountered the company's line of business intelligence and performance management tools branded as Cognos products. The name of these products is tied to a company of the same name that the computer maker acquired in 2007 for $4.9 billion. The deal was seen as a major step toward IBM becoming a top-level competitor of companies like Microsoft, with an extensive range of both hardware and software products.
Cleversafe
One of IBM's most recent acquisitions is Cleversafe. IBM purchased Cleversafe on November 6, 2015. The company developed an object storage system which was originally called Dispersed Storage Network but which has been rebranded post-acquisition as the IBM Cloud Object Storage service. This acquisition was another important step in IBM's movement toward cloud services.
This article is laughable. It does not even to being to cover the companies purchased by IBM. For example, The relatively recent purchase of Softlayer is not included. IBM has spent over $100b in share buybacks, and I would not be surprised that an even higher amount has been spent on trying to find the next golden goose.