Two challengers to Symbian's dominance of the handset operating system made their presence felt at 3GSM this week.
One was Microsoft, unveiling Windows Mobile version 6. The other was Japanese firm Access, who launched a mobile Linux group.
The new version of Windows Mobile operating system enables rich HTML email, closer integration with MS Office and stronger security, among other features.
Its launch comes as Microsoft, after years of struggling in the mobile OS market, can claim it is an established presence in the business.
Scott Horn, the head of Microsoft's embedded mobile devices division, said WM-powered phones were licensed to 48 different device-makers, with 140 different units shipped and with the support of 125 operators.
He said 5 million WM handsets shipped in the second half of 2006, compared with just 6 million for the previous 12 months.
WM runs on phones bearing the brands of most of the world's top handset-makers, including Motorola, Samsung and LG, as well as rising OEMs such as HTC/Dopod and China's Amoy.
Horn said that for now, WM will continue to focus on the high-end business user market, but it was only a matter of time before the focus turned to consumer segments.
He denied that Microsoft was planning a separate operating system based on the Zune music player platform. He said Zune might be ported as a service to run on Windows Mobile, but there were "no plans" to build out a Zune OS.
On the other side of the 3GSM exhibition, Access was promoting the founding of its new mobile Linux open source community, known as ACE. Among its 45 founding members are operators Orange, Telefonica and Sprint, chip-maker Texas Instruments and Japanese vendor Fujitsu.
Maureen O'Connell, senior director, corporate communications, for Access, said other mobile OS had been built based on a Linux core, but were not fully open.
She said the opportunity for Linux in the mobile space was that "operators and handset manufacturers are looking for flexibility, something they can customize, with an open architecture and not proprietary architecture."
Access also owns the Palm operating system and supported development on that platform as well as Access's own Linux OS and Java, O'Connnell said.