My husband is a programmer in CA. He’s never had a dress code. Shorts, Hawaiian shirts and flip flops? No problem. If there was a client in the office, they’d all dress up a bit (khakis, shirt with a collar, real shoes), but aside from that they could wear whatever they wanted.
I remember eyeing a pair of his shorts once because they were old and falling apart (but very comfy!). I asked if maybe that wasn’t pushing the no dress code thing a bit too far. A few days later, I happened to stop by the office and saw the CEO in jeans that were even worse! And no, not the allegedly fashionable pre-ripped look. These were just old, worn out, torn-but-comfy jeans. 