"Exploring a C program's memory use over time, on Linux" would be more accurate. Nothing in this article deals with our three spatial dimensions, the typical use of the word "space".
That seems unnecessary. Even a layman knows that in the context of a computer, space != physical space. Most people think of disk space, but it can also refer to memory usage [0]. The meaning of the name was obvious to me after reading the first half of the first sentence of the article. I thought it was clever :)
FWIW, all these things date back to the ancient Usenet "RTFM" (where M = manual) which would undermine an expansion of "featured" in my view (since manuals are not "featured", like links in news aggregators). The other alternative Fs still work, though.