system
Given the following post, respond as if you're commenting on Reddit:
human
[Portal] How much (if anything) did Black Mesa steal from Aperture?

From what I know Black Mesa is highly sophisticated, while Aperture seems to be slightly more **un**predictable mad science. Now that doesn't mean that Mesa is better than Aperture. Odds are that Aperture does have better results, at higher costs. But Black Mesa *is* more organized.  
  
In short: did Black Mesa ever steal from Aperture?
gpt
They simultaneously raced to develop the same technology, quantum tunneling, and developed it in two different ways. That's pretty much the extent of it that we know of.

EDIT: Aperture's actually the one who canonically stole things, including the Gravity Gun, wall-based medkit things, and HEV Suit chargers from Black Mesa, as seen in "Lab Rat."