Support for multithreading was absent, and the Proxy server operated in multi-process mode where each request was handled by a dedicated process.

A brand new http client, admin and installer GUI, and localization were the other major changes involved.

After acquisition of Sun Microsystems by Oracle Corporation in 2010, Sun Java System Web Proxy Server 4.0 was rebranded as Oracle iPlanet Web Proxy Server 4.0.

Oracle iPlanet Web Proxy Server 4.0 now supports the following new features: More information on new features, platforms support, and resolved issues can be found in the product release notes [1] While Oracle iPlanet Proxy Server 4.0.17 does not provide official Internet Content Adaptation Protocol (ICAP) support yet, version 4.0.17 is capable of talking to ICAP servers.

Official support may be added in a future release, subject to market demand and business justification.