Open Source primarily refers to some kind of coding being public domain and free to use and expand on.
Tumblelogs were what the first microblogs were called.
Microblogging refers to sending messages out via micro blogs. Twitter as an example is known as a microblog.
Static front page refers to a home page that you set in your wordpress dashboard that remains as the home page, no matter how many posts are added.
Blogcasting is the combination of podcasting and blogging on the one website.
Autocasting is an automated method of creating podcasts.
A podcaster is a person who creates podcasts (audio/video files) that are distributed on places like Itunes.
Podcasting is a popular method of distributing in particular audio files across online feeds for listeners to play back on pc and mobile devices.
Photoblogging is what a blogger does who predominantly features photographs on his or her blog.