They were called Verdana and Ohana. Ohana was the separate name for a bold version of Verdana. They'd been commissioned as potential scalable TrueType replacements for the bitmapped system font, MS Sans. When we commissioned the full screen font project that resulted in the Verdana we ship today, we asked for a sans serif and a serif family. For the serif, we leveraged off the existing verdana outlines, but Matthew redesigned them from scratch, since the objectives for this face were different.
Most type comes from the print world.
Since they were designed for print, people started by drawing the outlines, and bitmaps for the screen got generated from those. Hinting was applied to correct problems caused by bitmap rasterization. These were then used to draw the outlines, which were then hinted so they generated those exact bitmaps, but were also scalable. One of the features people notice first about Verdana, for instance, is that it sets very wide. Building additional intercharacter spacing into the font was one way we found of achieving better screen readability.