icalendar.rb is a Ruby library for parsing and generating iCalendar files.
ICalendar Validator checks the encoding and structure of your ICalendar resources against the ICalendar specifications.
ICalendar Aggregator aggregates events from multiple ICalendar feeds. It supports handling duplicates, multiple views (list, day, week), and manual input or correction of events.
A comprehensive tutorial and reference on shell scripting using Bash.
A standalone PHP library that extracts data from PDF files.