Following a number of highly successful, and in some cases astounding, stock-market flotations by Irish technology companies in recent months, there seems to be no end to the corporate appetite for the Nasdaq rollercoaster ride.

Riverdeep is barely out of the traps recording a 235 per cent rise in share value on day one on the Nasdaq, and SSL and Datalex are lining up behind to follow suit.

Although neither company has officially announced its exact launch date on the Nasdaq, both are likely to happen before the end of the summer.

Meanwhile tech-hungry investors, albeit largely institutional, are licking their lips in anticipation. While we are unlikely to see the same level of hoopla that surrounded Riverdeep's ascension and eventual float, SSL and Datalex are likely to be even more oversubscribed than Riverdeep. The reason is that both companies are fundamentally different from Riverdeep, and neither will require the same level of pump-priming.

This is not to say that Riverdeep is a turkey, but there is an element of dramatic stage production surrounding technology flotations that varies depending on the offering.

A company like Riverdeep only has one key barrier to entry, and that is its lead time in developing online educational content for the US primary school market. Over the past three to four years it has invested heavily in developing US curriculum compatible content.

However, there is nothing to stop a major player in the traditional educational media space, a large bookseller for example, entering this market aggressively. Therefore, Riverdeep will rely heavily on branding and marketing to retain its edge over looming competitors.

As one fund manager with Montogomery Oppenheim put it: "They spent a lot of money developing content and software, and this has been written off against the funds they raised. Now they just have to market the company aggressively. I expect they'll keep a steady stream of newsflow coming to keep the stock market interested."

Already, content partnerships with CNN have been mooted, and tie-ups with America On-Line (AOL) have also been hinted at.

Meanwhile, SSL and Datalex offer entirely different propositions. Neither is reliant on the public market to make or break the next phase of its strategy.

Both are reasonably cash rich, and both are involved in the provision of essential building blocks for the information age.

Alarm bells probably began to ring about SSL as a smart bet, when Goldman Sachs took a 23 per cent stake in the company which specialises in silicon-chip design. It was one of only three technology investments Goldman Sachs made in Europe in 1998.

Then the seven-year-old company refocused its business into intellectual property licensing, a strategy that has become very fashionable among similar scale companies based largely on brainpower.

This means SSL does not expose itself to highly volatile and costly semiconductor manufacturing activity, preferring instead to base its revenue model on its people. A similar company which has already gone the public route is Arm Holdings in the UK, which currently has a market capitalisation of more than £9 billion sterling (#14.57 billion).

Datalex specialises in providing software to the profoundly technologically challenged airline industry.

It has grown over 15 years by stealth and strategic acquisition. Its progress has also been facilitated by the dire straits in which the notoriously archaic airline industry has found itself. By operating independently it has been flexible in adapting to rapidly changing market requirements following the Internet's arrival.

Two years ago the company employed around 50 people and had a turnover of $10 million (#10.27 million). Now it employs 375 people globally and is almost certain to exceed a revenue target of $45 million this year.

This week one industry observer described Datalex as one of the few companies globally that could offer any kind of a technology solution to airlines which were getting their "butts kicked by the likes of leaner operations like Ryanair".

Speculation abounds about whether the tech bubble is about to burst, but at the chalk face, where the deals are done, there is a distinct feeling that tech mania is only beginning to build this side of the water.

European retail investors are only beginning to get into their stride, and still have a long way to go before they drive the overall market as is currently the case in the US.

Meanwhile, the European tech market remains very much the preserve of investment institutions which are practically scrabbling for high-tech plays.

This is likely to remain the case for the more conservative European companies coming to market, which prefer the reliability of a tried and trusted institution over the hit or miss approach of the retail investor.

According to Datalex managing director, Mr Neil Wilson: "I'm quietly amused by the feeding frenzy on new public listings. I think retail investors don't do sufficient homework on their investment targets. The institutional investor tends to be much more sophisticated in his long-term view."