Houghton Mifflin Co. News Release - May 31, 2006

Houghton Mifflin Company Acquires SkillsTutor™ from Achievement Technologies, Inc.

BOSTON — May 31, 2006 — Houghton Mifflin Company today announced an agreement with Achievement Technologies, Inc. (ATI), a privately held educational software solution and service company, to acquire all of ATI's research-based instructional products for $18.5 million in cash, as well as certain commissions, contingent payments of up to $4 million and other payments by the Company to and from ATI. The Company also entered into an Option Agreement pursuant to which the Company has the right to exercise an option to purchase certain retained assets of ATI.

SkillsTutor, ATI's flagship product, is an award-winning, internet-based supplementary instruction and tutoring program with more than 1,600 lessons and tutorials. SkillsTutor provides diagnostic and prescriptive assessments, pre- and posttests and a management system that monitors student progress. The program is used in a variety of Title I, special education, before-, during- and afterschool programs, summer school, intervention and community learning centers.

SkillsTutor helps students master core skills and improve standardized test performance through web-based, step-by-step instruction, individualized assessments and personalized tutoring in core disciplines such as reading, writing, language, math, science and information skills.

In addition, the Company also acquired the popular SkillsBank, CornerStone, and Employability Skills products from ATI.

"As a proven solution for supplemental instruction, SkillsTutor is a great addition to our K–12 offerings," said Tony Lucki, president and chief executive officer, "The acquisition of these ATI products underscores our commitment to bring the most effective tools to our customers to support their needs in the classroom."

About Achievement Technologies
Achievement Technologies is a privately held educational software solution and service company founded in the fall of 1999, focusing primarily on the K–12 school market with a secondary focus on the school-to-work and adult basic skills market. ATI is a market leader in K–12 remediation and core skills building. Its proprietary products span all grade levels (K–12 and adult markets) and can be delivered to customers on all platforms including the Internet, network versions or CD-ROM.

About Houghton Mifflin
Boston-based Houghton Mifflin Company is one of the leading educational publishers in the United States, with more than $1 billion in sales. Houghton Mifflin publishes textbooks, instructional technology, assessments and other educational materials for elementary and secondary schools and colleges. The Company also publishes an extensive line of reference works and award-winning fiction and nonfiction for adults and young readers. With its origins dating back to 1832, Houghton Mifflin combines its tradition of excellence with a commitment to innovation. The Company's Web site can be found at www.hmco.com .

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