net-status-monitor is a simple console script to test whether Internet connectivity is working. If it is, the script tells you the external IP address (in case your dynamic DNS provider is down). If not, it tries to find the point where the connectivity fails. The output is quite simple, so you can put it on your grandmother's PC. "Just tell me what the read line says" should give you enough information.
Hoteldruid is designed to manage weekly or daily rental of house apartments or hotel rooms. It uses a PostgreSQL, MySQL, or SQLite database as a backend. Reservations can be assigned to rooms automatically with user-defined rules. Pages with forms to check availability for Internet sites can be created. It supports multiple users with a privileges system. Documents and invoices can be printed, saved, and emailed.
Byteflow is a blog engine written on Django. It features Markdown and typogrify for posts and comments, threaded comments, automated registration for a user after comment posting (no anonymous users), registration approval/email changing/profile editing, tags (and filtering posts by tag), the ability to have translated names for tags, archives by day, month, and year, Atom and RSS Feeds for posts, comments, comments for a specified post, posts within a specified tag, and OpenID support. It supports multiple OpenID URLs attached to a single user, a Wordpress importer, Gravatar, an optional WYSIWYG editor in admin parts (for posts, not for comments), and LiveJournal crossposting.
Monjo is a Web application that helps monitoring a small to medium network of servers. It offers easy customization of notifications in case of network failures and is designed to allow for easy addition of new services that need to be monitored. It's internationalized and includes a Web interface in English and German. It currently supports notifications by email and can check services using ping, SMTP, HTTP, POP3, and IMAP4.