It's a bit like journo and uni (for university). It's a kind of diminutive. It is as if people so little regard the institution they are talking about that they can't be bothered to finish off its name.
So you approach the Archiweb site with very mixed feelings. As you've guessed from the suffix cz it's a Czech site. And despite the english česky tags, its text is resolutely in Czech.
Click on ARCHITECTS and there at the top is a closeup of somebody's eyes with a hand clutching their right ear and ...aaaargh, it's Zaha. Hope she knows, or perhaps not. But you then have to ask why our own Czech diva, the wondrous Eva Jiricna, is not plastered all over the banner. Prophets in their own country, methinks.
When you click on an architect's name you mostly get full details in Czech including the practice website. And here's an intriguing feature which you are beginning to see on other sites. When you click on the national flag just after the crosshead 'tel:' up flashes Skype ready to dial a call to the principals. But only if you have Skype installed in the first place.