1. Architecture: LiteSpeed is a standalone server that is designed from the ground up for speed and efficiency. It utilizes a multi-threaded architecture, allowing it to handle a large number of concurrent connections. On the other hand, OpenResty is not a server itself, but rather a web platform that integrates with Nginx to provide additional functionality. It uses an event-driven, asynchronous architecture that is optimized for handling high volumes of traffic with low resource usage.

2. Programming Language Support: LiteSpeed natively supports various programming languages such as PHP, Python, Ruby, and Java. It also offers support for popular web applications like WordPress, Magento, and Joomla. In contrast, OpenResty is primarily designed for the Lua programming language. It provides an embedded Lua runtime environment that allows developers to write server-side application logic directly in Lua.

3. Caching Mechanism: LiteSpeed offers a built-in caching mechanism that can significantly improve website performance. It includes features like page-level caching, object-level caching, and private cache. LiteSpeed's caching is easily configurable and requires minimal effort to set up. On the other hand, OpenResty does not have built-in caching functionality. However, it can be extended with third-party caching modules such as Lua-resty-lrucache or Lua-resty-redis, which provide similar caching capabilities.

4. Security Features: LiteSpeed places a strong emphasis on security and includes several features to protect websites from threats. It offers real-time malware scanning, DDoS protection, and advanced access controls. LiteSpeed also provides an integrated web application firewall (WAF) that helps administrators detect and mitigate web-based attacks. OpenResty, on the other hand, does not provide these security features out of the box. However, it can be combined with additional modules or services, such as ModSecurity, to enhance security.

5. Community and Support: LiteSpeed has a well-established community with active forums, documentation, and regular software updates. It offers professional support services for both free and paid versions of the software. OpenResty also has a growing community and documentation resources, but it may not be as extensive as LiteSpeed's. While community support is available, professional support options for OpenResty may be more limited.

6. License and Pricing: LiteSpeed has a proprietary license and offers both free and paid versions of its software. The free version, LiteSpeed OpenLiteSpeed, has certain limitations but is suitable for basic websites. The paid versions, LiteSpeed Web Server and LiteSpeed Enterprise, provide additional features and performance enhancements. OpenResty, on the other hand, is open source and available under the BSD license. It can be used and modified freely without any licensing fees.

In Summary, LiteSpeed and OpenResty differ in their architecture, programming language support, caching mechanism, security features, community and support, as well as their license and pricing models.