Since the WebTV set-top box was a dedicated web-browsing appliance that did not need to be based on a standard operating system, the cost of licensing an operating system could be avoided. The box featured a 64-bit RISC CPU, 2 MB of RAM, and a smart card reader. The smart card reader was not utilized significantly. The web browser was compatible with both Netscape Navigator and Microsoft Internet Explorer. The first WebTV set-top boxes had a 33.6 kbit/s modem, and later versions had 56kbit/s modems. The WebTV set-top boxes leveraged the service's server-side caching proxy which reformatted and compressed web pages before sending them to the box, a feature generally unavailable to dialup ISPs users at the time and as such, had to be developed by WebTV. For web browsing purposes, given WebTV's thin client software, there was no need for a hard disk, but by putting the browser in non-volatile memory, upgrades could be downloaded from the WebTV service.