In 2000, Joe Britt, Matt Hershenson and Andy Rubin formed Danger Incorporated. Danger developed the world’s first recognizable smartphone, the Danger HipTop. T-Mobile sold the first HipTop under the brand name Sidekick in October of 2002.
Danger had a well developed kernel that had been designed and built in house. The kernel came to be viewed as not a core intellectual property and Danger started a search for a replacement. For business reasons, mostly to do with legal concerns over the Gnu Public License, Danger rejected Linux and began to consider BSD Unix as a replacement for the kernel.
In 2006 I was hired by Mike Chen, the manager of the kernel development group to investigate the feasibility of replacing the Danger kernel with a BSD kernel, to select the version of BSD to use, to develop a prototype and to develop the plan for adapting BSD to Danger’s requirements.
NetBSD was easily the best choice among the BSD variations at the time because it had well developed cross development tools. It was easy to use a NetBSD desktop running an Intel release to cross compile a NetBSD kernel and runtime for a device running an ARM processor.
(Those interested in mailing list archaeology might be amused to investigate NetBSD technical mailing list for mail from picovex, particularly from Bucky Katz at picovex.)
We began product development on the specific prototype of the phone that would become the Sidekick LX2009 in 2007 and contracts for the phone were written with T-Mobile. We were about half way through the two year development cycle when Microsoft purchased Danger in 2008.
Microsoft would have preferred to ship the Sidekick running Windows/CE rather than NetBSD, but a schedule analysis performed by me, and another by an independent outside contractor, indicated that doing so would result in unacceptable delay.