This is a Frankenstein version of QRCode.js with some of the countless pending pull requests applied (the ones I deem useful).
Apparently the original author has abandoned the project, which again illustrates the need for for other people to be able to take over an abandoned GitHub repository.
qrcode.js is released under the MIT License.
Some extra hocus pocus has been added to allow saving generated SVG images. (Setting width different from height doesn't work with SVG, but makes little sense in general anyhow.)