One-time FE account
Allow users to create a short-lived FE user account without having to enter a user name or password.
Seminar Manager
Allows you to create and manage a list of seminars, workshops, lectures, theater performances and other events, allowing front-end users to sign up. FE users also can create and edit events.
Cart - Events
Shopping Cart(s) for TYPO3 - Event Extension
Workshops system
Flexible workshop and courses management.
seminars/cal redirect
This extension creates a redirect from cal to onetimeaccount/seminars.