Quadrant Software LLC has purchased two software companies as a means of expanding its services.

Mansfield, Mass.-based Quadrant, which produces software for the IBM iSeries operating environment, acquired Business Computer Design Inc. (BCD) and ExcelSystems Software Development Inc. (ESDI). Both companies are web development specialists that also make IBM iSeries products.

Victoria, BC-based ESDI is the development arm of Chicago-based BCD, and the two companies have been partners for more than 20 years, according to a statement. They will continue to operate under their own brands.

Quadrant is owned by private equity firm Candescent Partners, which invested $17.75 million to gain a control stake in the company in December 2010.

Brooke Private Equity Associates, Bush O’Donnel Capital Partners, Harbert Mezzanine Capital and Massachusetts Capital Resource Company were co-investors in the deal at the time.

Quadrant’s two main products, FastFax and Formtastic, concentrate on “revenue critical” documents, such as purchase orders and invoices.

Candescent, formed in 2009, has made many acquisitions. The firm’s first deal was a $21 million investment in the Center for Wound Healing and Hyperbaric Medicine in September 2009. The Tarrytown, N.Y.-based company was renamed Candescent Healing and sold in January 2013 to RestorixHealth Inc.

Technology