JSONView is a nice add-on for Firefox to view the JSON responses mentioned in the following sections.
Use heroes.php to get a JSON formatted response of the DOTA heroes.
Use items.php to get a JSON formatted response of the DOTA items."
Use guides.php to get a JSON formatted response of the DOTA guides."
Use heroes.php?callback=yourcallbackname to get a JSON-P formatted response of the DOTA heroes.