SilverStream Golden in IPO

This summer has witnessed an initial public offering market of the haves and the have-lesses.

SilverStream Software Inc., whose products help companies create their own software for electronic commerce, nearly doubled Tuesday in its first trading day. But other IPOs are getting chillier greetings.

Burlington, Mass.-based SilverStream (ticker symbol: SSSW) rocketed $15.50 to close at $31.50 on Nasdaq, giving it a market value of $534 million.

The gain follows big jumps last week for some software-related Internet IPOs, such as Red Hat Inc. and Quest Software Inc., both of which tripled on their first trading day. But other Net companies have been forced to postpone or cut their IPOs in this picky environment.

Laser vision correction firm NovaMed (NOVA) was blindsided Tuesday. Its IPO was priced at $8 after reducing its expected range to $9 to $10 from $11 to $13.

Also Tuesday, online printing firm Imagex.com lowered its range to $8 to $10 from $12 to $14, while Tunes.com, an online music network, cuts its range to $9 to $11 from $13 to $15.

Meanwhile, hoping to join the haves, San Mateo, Calif.-based E-Stamp Corp., a Web postage company that recently got government approval for its services, filed for an $85-million IPO.