Rivendell house brand that stands for "made in USA." Under this label, Rivendell produces a line of clothing and accessories, including the knickers and pants that are designed specifically for cycling, but are described as being wearable "anywhere when formal wear isn't called for." The Co-Habitant ordered both the knickers and the long pants over the summer, because he was wearing out all his regular pants on long rides, and he thought these would be more durable. He immediately loved them and kept recommending them to me - until I finally bought a pair of knickers myself a couple of months later. Our impressions of this product are somewhat different, and put together they will hopefully be informative for both genders.
All in all, the Musa pants and knickers are excellent if you want to wear something comfortable and durable on a roadbike, and if you are male. If you are female, consider the issues with fit and compare how the pants look on a male vs a female body. For me, the gusset and other positive features are worth it - but only because I found no better alternatives. And I would never wear these knickers in a context other than on a roadbike, which does diminish the value of what was meant to be a "wear them anywhere" design.