The 2005 Agenda Setters panel proved that though they believe the predictable government officials and big-name tech CEOs do indeed influence the IT industry, those fighting the established order are also ones to watch.

One arena that's seeing plenty of shaking up is telecoms, with voice over IP (VoIP) on the rise as a way to circumnavigate the standard telephone system and place voice calls over the internet for free, or very cheaply.

Two men - Skype CEO Niklas Zennström at number four and Vonage CEO Jeffrey Citron at 36 - claimed a spot on the list for being leaders in the VoIP revolution.

VoIP is stealing voice revenues from incumbents and forcing them to play catch up. However, the extent to which the big telcos are threatened by the new technology was debated by the Agenda Setters panel.

Martin Brampton, consultant and Agenda Setters panellist, said: "You can argue that VoIP is setting the agenda, you could argue that. Or you could say... that BT is setting the agenda. They've seen the decline of voice revenue coming for years. They fully understand this. They're in a situation of simply raking in the money for as long as it's available. They're not fooled by this."

Simon Briskman, partner at law firm Olswang and Agenda Setters panellist, added that incumbent telecoms companies are doing quite well at building IP networks and rolling out services on them - and so it might not be long before they regain power. He said: "[VoIP is a] disruptive technology but I wonder if it's just an interim technology before we get back to big telecoms dominating the market."

Judging by the voting, the panel did decide in the end that Zennström and Citron deserved a place on the list on the back of VoIP's threat - even if the telcos eventually triumph, either by acquiring the upstart VoIP companies or matching their offerings.

Open source is another arena, long represented on the Agenda Setters poll, which by the very fact it is opening up source code to anyone is challenging the established order of software development.

Linus Torvalds, a perennial Agenda Setters favourite who's appeared on the list every year since the poll's inception, fell four spots from last year to number 11, revealing how the panel feels his influence has waned. Nonetheless he's still seen as the figurehead of the movement.

Brampton said: "He still maintains a close grip on Linux, which is a pretty core element of the open source movement, one of the validating elements of the whole thing."

The open source browser Firefox was seen as an even more disruptive threat in the web browser space, where it could play a key role in loosening Microsoft's grip on the desktop. For this, Mitch Kapor, chair of the Mozilla Foundation, the organisation responsible for Firefox, debuted on the list at number 23.

One panellist noted that the open source campaigners can't do it all alone, though, and need the backing of big business.

Russell Altendorff, IT director of the London Business School, said: "I think IBM made the difference to Linux becoming a legitimate and major brand in IT. When Linux was ported to a mainframe, that was it, suddenly 'Oh, OK, it really is a serious operating system'... The same thing could happen with Firefox. It's early days."

Free software advocate Richard Stallman also got the nod at number 29 for his vocal role in the open source movement and other anti-establishment causes. But compared to last year, the list includes half the number of individuals involved in open source - perhaps proof of how the software model is becoming more mature, accepted and thus taken for granted.

The anti-establishment contingent won two more spots: anti-software patent activist Florian Mueller (number 43), and Simon Davies and Gus Hosein (45). Davies and Hosein earned a spot for their work on the LSE's Identity Project, which is subjecting the UK government's plan to roll out national identity cards to intense scrutiny.

Though these Agenda Setters placed low on the list, the issues they represent could be the ones most threatening to the established power structure.

Legalising software patents would be most beneficial for those organisations rich enough to defend their creations - and most detrimental to the small-timer unable to fund such a legal battle.

And the implications of a government rolling out ID cards stretch far beyond technology - to the sociological and political realms, potentially threatening citizens' civil liberties.

Richard Sykes, consultant and Agenda Setters panellist, said of the Identity Project: "One's actually seeing for the first time a major government initiative being subject very early on to a massive critical analysis."

These individuals may not change the world but they are influencing the realms in which they operate. Their inclusion on the list shows the panel's inclination to commend not only those who understand how to succeed in the existing power structure but also those doing the tougher job of redefining what that structure looks like.