X0202 4 2006-04-10 0 0000877931 ARTISOFT INC ASFT 0001044321 MARXE AUSTIN W & GREENHOUSE DAVID M C/O SPECIAL SITUATIONS FUNDS 527 MADISON AVENUE, SUITE 2600 NEW YORK NY 10022 0 0 1 0 Common Stock 2006-04-10 4 P 0 4500 0.66 A 11649736 I By Limited Partnerships This is a joint filing by Austin W. Marxe (Marxe) & David M. Greenhouse (Greenhouse). They share voting & investment control over all securities owned by Special Situations Fund III QP, L.P. (SSFQP), Special Situations Cayman Fund, L.P. (Cay), Special Situations Private Equity Fund, LP (PE), Special Situations Technology Fund, L.P. (Tech) & Special Situations Technology II, L.P. (Tech II), respectively. 5,831,195 shares of CS, 1,197,992 Wts to purchase 324,553 CS are owned by SSFQP, 2,011,310 shares of CS, 433,206 Wts to purchase 116,539 CS are owned by Cay, 1,963,649 shares of CS, 431,930 Wts to purchase 115,263 CS are owned by PE, 188,765 shares of CS, 37,206 Wts to purchase 9,931 CS are owned by Tech, and 1,038,138 shares of CS, 189,785 Wts to purchase 50,393 CS are owned by Tech II. The interest of Marxe and Greenhouse in the shares of Common Stock & Warrants owned by SSFQP, Cay, PE, Tech, & Tech II is limited to the extent of his pecuniary interest. Austin W. Marxe 2006-04-12 David M. Greenhouse 2006-04-12