Transitive Corporation has announced new hardware emulation technology, plus agreement with two SGI software developers to develop new applications with it.

Dubbed Quick Transit, Transitive's technology allows software compiled for one processor and OS to run on another, with changes in neither source nor binary code. In other words, it's a hardware emulator, although the company is careful not to mention the word emulation - hardly surprising given the number of failed attempts that litter IT's history books.

Previous failures include Digital's FX!32 which ran x86 software on Alpha chips and Transmeta's attempt to run x86 code on its low-power Efficeon processors. Instead, the company calls it hardware virtualisation.

What makes it significant is that Apple has been testing QuickTransit for months, as Steve Jobs has confirmed. Calling the technology Rosetta, Apple intends to build it into its OS when its ships its first x86-based Macs next year.

"Apple made the switch to Intel because they had translation software - the risk is enormous and they tested this before they decided to make the move", said chief technology officer and founder Alisdair Rawsthorne.

According to Rawsthorne, the technology works by translating CPU instructions on the fly, building a list of translated instructions into a code cache. On second execution, instructions are pulled from the cache. The system also optimises sections of code that it detects are frequently called. The result is that there's a 20 per cent performance penalty for the emulation, and a 25 per cent memory overhead, according to Rawsthorne. Graphics tasks experience a lower overhead, and CPU-intensive one much higher, maybe up to 40 per cent.

We saw a demo and briefly tried the system, switching between applications written for x86 and running on an SGI MIPS machine and vice versa, and x86 applications running on an Power5-based Apple G5. In its favour, in all cases, the user interface's response was as fast as it would be if it were native. We manipulated an onscreen 3D image with no visible performance deterioration. However, we also saw no benchmarks, and ran no CPU-intensive tasks, nor did we get a chance to try any applications that hadn't been pre-loaded.

If the demonstration is typical, then this is the best manifestation of this technology that we've seen. It's a big if, though, and we remain sceptical, given the poor track record of hardware emulation - it has almost always failed - and want to see it given a considerably more thorough workout.

Meanwhile, Apple's endorsement of the technology is important for the company, and it hopes to expand its list of hardware and software vendors packaging its technology. In particular, hardware emulation inside a virtual machine looks like an attractive option from a server and development perspective, and Transitive CEO Bob Wiederhold said his company is talking to VMware with this in mind. Transitive also intends to sell QuickTransit as a retail product at some point in the future.

Could this be the right moment for hardware emulation? Given the speed of today's hardware, a performance penalty of even 40 per cent could, from an end user perspective, make little difference to many applications. However, compatibility is a big issue, and Apple is not claiming 100 per cent compatibility for Rosetta, although Transitive raised no such caveats.

The company, which developed the technology at Manchester University and conducts its R&D there, has based its HQ at Los Gatos, California. Transitive was started in 2000 after five years of development effort at Manchester, and has raised some $24 million in three rounds of funding from VCs Pond, Crescendo and Accel. It has about 65 employees.

The two ISV partners whom Transitive has just announced are Opticore and UGS.