I understand that passwords should be encrypted in databases to protect them from hackers and people with bad intentions. But MD5 was renewed in 2005. Since then, hackers found the inverse hash function and a lot of website can easily crack the MD5 hashed key, for example md5this.com which was one of the first suggested on google.
Shouldn't each web developper create their own hash functions so that the hackers can't retrieve the password if they get access to the database ?