ELOG Electronic Web Logbook is an electronic logbook with a Web interface. It can be used to maintain personal or shared logbooks, with the ability to add attachments to logbook pages. Logbook entries can be categorized with user-defined classes, and queried using filters on these classes. Automatic email notifications can be generated on new entries based on the classes. The ELOG server is a small stand-alone C program, which runs under Linux and Windows. No other packages are required. The logbooks are saved in plain ASCII files for easy and fast access.