This address held the first version of the tool. The later build, which replaced it on the front page, linked back here as the legacy website and noted in brackets what it offered: heart rate, climbing and the other channels that the newer, narrower version had dropped. Speed alone was easier to explain and harder to make internally consistent.
What the earlier build altered
Where the later tool changed speed alone, this one reached further into the file. Heart rate could be adjusted, as could climbing, which meant an altered activity could be made internally consistent in a way a speed-only change never quite managed on a route with any gradient. A faked climb with an unchanged heart rate gives itself away immediately.
That thoroughness is presumably why it was kept available rather than removed. It is also why it was the more pointed piece of satire: a file with plausible speed, heart rate and climbing is far harder to dismiss on inspection than one with only the first. Each additional channel it touched made the result that much more coherent.
Why this address still receives traffic
Forum posts and articles from the period frequently linked to this page specifically, not to the front of the site, because the earlier build was the one people discussed in detail. Those links still resolve, which is the reason this description exists at the original address. Removing the page would have broken every one of them at once.
The page is a description, not a restoration. No version of the tool runs here, and the code is not published. What remains is an account of what stood at this address and why a considerable amount of cycling writing from the period points at it. The behaviour it demonstrated is documented; the means of repeating it is not.
The rest of the period is described in the archive. Current work is at the instruments.