Here are some recent improvements here and in Polygon.
Weak and Leaked Passwords
We often hear about password leaks from various services. Considering that having common passwords is a common (but insecure) practice, we've improved Codeforces and Polygon to identify weak or leaked passwords. If on the top of the website you see a message that your password is not secure, then just change it immediately.
Type of the round when creating a contest proposal
This item improves our work with the writers. When creating a contest proposal, please indicate the type of a round. Leave the field empty only if you don't know the type of the round (it is strange).
We've fixed errors when synchronizing official Codeforces rounds with the calendar. Now everything should be correct.
I trust this user
Currently, Codeforces provides a mature infrastructure for organizing contests, olympiads and trainings. With the help of domain groups and mashups, competitions of various levels were hosted on Codeforces. The organizers are sometimes not regular users of Codeforces rounds and do not have rights to some of the actions. Now, any red user can confirm his trust in another account, and he will get the right to: write comments/posts, create private groups, create mashups. I hope this will save me from a certain routine of processing such requests.
Confirmation via email when entering Polygon
When you sign in Polygon, your IP-address and browser will be verified. If you didn't use them in the recent past, then you may be asked to sign in with a confirmation email. In this case, just follow the secret link that comes to your email.