The BBC's iPlayer online video service has won a cautious welcome from the first people to download and use it.
Popular programmes such as Dr Who will be on the iPlayer
On chat forums triallists complained about technical problems but others were complimentary about the content on offer and download speeds.
The BBC began a limited sign-up period for the service on 27 July.
The iPlayer lets people in the UK download BBC programmes broadcast in the last seven days and watch them any time in the following 30 days.
Since 27 July, the message board set up for triallists has been busy logging praise and problems from those who downloaded it soon after it became available.
As might be expected many of the problems people posted messages about were to do with installing the software.
Many reported being confused by an error message which told them that the iPlayer needed Internet Explorer 7, Windows Media Player 10 and some components of Windows XP even though all were present.
In many cases updating to the latest release of these components, such as the Windows Media Player, cleared the problem.
Some saw "security errors" caused by the Microsoft security system used to prevent piracy of downloaded programmes.
Once triallists had the iPlayer installed, early experiences differed widely. Some reported very fast download speeds but others waited hours to get only a small percentage of the show they wanted to see.
On the message boards, BBC support staff said experiences might vary because of the peer-to-peer technology used to distribute the programmes. Generally, the more people who download a show, the faster it tends to get distributed to others.
The iPlayer makes about 400 hours of programming available but some said more should be forthcoming and dismissed the current line-up as "silly froth".
Many of those posting on the message boards had suggestions about how to improve the service.
Some called for the BBC to throw open its archive to get at classic shows but others wanted new features such as a "series stacker" that automatically downloads the latest episodes of favoured programmes.
iPlayer will allow viewers to catch up on TV programmes for seven days
Some TV series can be downloaded and stored for 30 days
Viewers will be able to watch shows streamed live over the internet
Users cannot download programmes from other broadcasters
Classical recordings and book-readings are excluded from iPlayer
The BBC ran a small-scale trial of the iPlayer for some time. About 15,000 people are thought to have taken part in this with about one-third being regular users.
The BBC has not revealed how many people it plans to sign up for the beta, or trial, but numbers are expected to grow significantly in 2007 and beyond.
The iPlayer is one of several download services run by the UK's broadcasters. For instance, Channel 4 runs the 4OD service that lets people download and watch programmes broadcast by the channel.
The BBC's iPlayer has faced criticism from some quarters. In particular, many critics have taken issue with the decision to, so far, restrict its use to PCs running Microsoft Windows XP. Versions for Windows Vista and Mac are expected to follow soon.
Many of the comments sent in to the BBC in the wake of the launch called for the iPlayer to work on computers that did not run Windows.
Open source advocates want the corporation to produce a version that works on the popular Linux operating system.
The BBC Trust, which oversees the corporation, has said the broadcaster must open up the iPlayer as soon as possible and plans to review progress every six months.
The iPlayer has been hailed by Mark Thompson, the corporation's director general, as a development as significant as the start of colour TV.