Citizens of the European Union can now buy an Internet domain bearing the .eu suffix.
The public are getting the chance to buy .eu domains following a four-month period that let firms reserve domains to match their trademarks.
More than 300,000 organisations used the so-called sunrise period to apply for a .eu domain.
Interest in .eu is expected to be high as speculators snap up the most popular domain names.
"Nobody knows exactly how many registrations of new domain names to expect," said Marc van Wesemael, head of .eu administrator Eurid, in a statement. "But the interest so far has been significant."
Some are expecting the .eu domains to be very popular and said they had been getting lots of enquiries from members of the public.
Markus Eggensperger, Lycos legal and PR director for domains, said there was more public interest in .eu than for any other newly launched domain.
"It's the most important top level domain we have ever seen," he told the BBC News website.
Interest was high, he said, because the population of potential applicants was so large and because of what the .eu domain might become. He said eventually .eu could challenge .com in importance.
Backed by the European Commission, the .eu domain is intended for organisations and people based in the 25-nations of the trading bloc. More than 1,500 firms have signed up to sell the .eu domains at prices ranging from 12 to 100 euros.
The sunrise period was run in two stages. For the first two months from 7 December 2005, public organisations and trademark holders could apply.
On 7 February those who had owned "other rights" could apply and all EU citizens get the chance from 7 April.
During the sunrise period, more than 335,000 applications were received and 95,000 of those are known to involve conflicting claims for domains.
For instance the www.polo.eu domain was applied for by car maker Volkswagen, fashion house Ralph Lauren and sweet maker Nestle. The domain has been awarded to Volkswagen which got its application in first.
Similarly, the Discovery Channel has won control of www.discovery.eu beating Land Rover which put its application in four minutes after the sunrise registration opened.
"The alarm bells should be ringing for any company which has yet to secure its trademarks in .eu," said Jonathan Robinson, chief operating officer of NetNames.
Speculators who are applying for the most coveted domains could also have a tricky time securing a name. The system is run on a first-come, first-served basis.
For instance, there are more than 280 applications to control the www.sex.eu domain, 220 of which were filed on the same day.
Many of these applications have expired because of missing paperwork, but it could take time to work out who has the best claim to generic and potentially profitable domains.
According to statistics provided by .eu domain registrar Eurid, Germans have been the most active registrants of domains so far. More than 28% of applications have come from Germany. The UK was fourth behind the Netherlands and France.
Thousands of domains of relevance to the European Commission have been reserved and cannot be bought by anyone else.