Institutional demand for the shares was such that the firm not only reached its target of raising pounds 3.6m in new money, but also allowed institutional shareholders, including the Cheshire Council pension fund and Murray Johnstone, to sell shares worth pounds 4.2m.
The flotation values the company, which is joining the AIM junior market, at pounds 18.9m. Its shares, which have been priced at 200p, are due to start trading on June 15.
The new funds will allow JSB to launch a marketing campaign for its SurfControl Internet product in the US and the UK. The package allows companies to control employees' access to the Internet by authorising or blocking certain sites. .
The company also sells products which take applications based on the Unix server language and make them look like user-friendly Windows applications. In the 10 months to March, it made a pounds 10,000 profit on sales of pounds 2.36m.