Commercial, property and litigation specialist Rosling King has installed the information package OfficeTalk.
The London-based firm was looking for a system to organise employees' time and let them communicate effectively, and it says the package has increased productivity.
IT manager Joyce Campbell said: "We needed a system which enabled people to coordinate activities in a timely fashion. Lotus Organiser was good but OfficeTalk beat it."
The system will eventually be installed on 60 PCs after 13 users from the firm, including senior partners and support staff, tried it. The firm said features like the ability to see individual diaries side by side and the way the system notified staff of their commitments had improved daily business life.
Tim Lawes, of Sareen Software, the company that created OfficeTalk, said the product allowed the firm to use its existing network for far more than sharing files. He said Sareen would continue to take on software Goliaths Microsoft and Lotus.