Stephen W. Boudreau, 57, of Natick and formerly of Newton, died unexpectedly Thursday, April 14, 2011, at MetroWest Medical Center in Natick. He was the beloved husband of Margaret M. (MacKinnon) Boudreau, with whom he shared 30 years of marriage. A Natick resident for 13 years, he was born in Newton, the son of Rosemary (O'Connor) Boudreau of Newton and the late John Boudreau. Mr. Boudreau was a freelance technical writer in the computer industry for more than 35 years. He attended the Newton School System, graduating from Newton High School in 1972, and graduated from Suffolk University in 1978. A lifelong advocate of physical fitness, he ran the Boston Marathon three times and participated in numerous triathlon competitions. He was an avid Red Sox fan and enjoyed a variety of music ranging from classical to blue grass to Jimi Hendrix. In addition to his wife and mother, he is survived by two children, Kyle J. Boudreau and Alexandra M. Boudreau, both of Natick; two sisters, Barbara Demosthemous of Jacksonville, Fla. and Andree Boudreau of Westwood; two brothers, Mark Boudreau and his wife, Millie, of Newton, Daniel Boudreau of Somerville; and several nieces and nephews. He was also the brother of the late Betsey Barisano. Relatives and friends are invited to attend visiting hours Tuesday, April 19, from 4 to 8 p.m., at the John Everett and Sons Funeral Home, 4 Park St., at Natick Common. Burial services will be private. Expressions of sympathy may be made in Stephen's memory to the Juvenile Diabetes Research Foundation, 60 Walnut St., Wellesley, MA 02481. For directions or to send online condolences please visit www.everettfuneral.com.