jZebra is a Java applet which allows you to print barcodes, receipts, and more from a Web page to your industry printer. It sends raw print commands and basic HTML and PDFs to your raw, PostScript, or LaserJet printer. It has been tested with Firefox, Safari, Internet Explorer, Chrome, and Opera. It supports parallel, serial, USB, and network printers.
ivykis is a library for asynchronous I/O readiness notification. It is a thin, portable wrapper around OS-provided mechanisms such as /dev/poll, epoll_create(2), kqueue(2), poll(2), and port_create(3C). ivykis was mainly designed for building high-performance network servers, but can be used as building block for any kind of event-driven application that uses poll(2)able file descriptors as its inputs.