I recently had the opportunity to sit down with my mentor, Schimon Jehudah, for an intensive technical session. We spent time deconstructing XMPP, and it was eye opening to see how it compares to the traditional web architectures most of us are used to.
Here is a summary of the core concepts we discussed—perfect for anyone looking to understand what makes XMPP unique.
XMPP vs. HTTP: A Different Philosophy
The biggest takeaway was how these protocols handle data. In the HTTP world, you typically rely on separate server side software to manage your data.
However, modern XMPP servers like eJabberd, Prosody, Tigase, and Jabberd2 are designed to integrate both communication and data management into a single, unified operating environment. This architecture allows the server to handle more than just passing messages; it manages the state and data of the application itself.
The Foundations: RFCs vs. XEPs
We broke down the ecosystem into two main categories:
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RFC (Request for Comments): This is the “Communication Layer System.” It’s the foundational manual that ensures the protocol works consistently across different platforms.
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XEP (XMPP Extension Protocol): These are modular extensions, similar to plugins. While RFCs handle the “how” of communication, XEPs handle the “what”—the specific data management practices.
The Power of Modularity
XMPP is inherently modular. This means the system is built from independent parts that don’t rely on each other to function. For developers, this is a huge advantage: you only implement the specific XEPs you need, keeping your build lean and highly customized.
Data Formats: XML over JSON
While most web developers today gravitate toward JSON, XEPs explicitly define and prefer XML for managing and communicating data. This provides a robust, structured way to handle complex data across the network.
Critiquing the Terminology
One of the most interesting parts of our discussion was how certain names in the XMPP world might actually hide their true potential from new developers:
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PubSub vs. Storage: XEP-0060 (Publish-Subscribe) is frequently used for data storage, but the name doesn’t make that obvious. Many developers assume XMPP can’t handle storage like HTTP simply because of this naming convention.
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Microblogging vs. Publishing: XEP-0277 is titled “Microblogging,” but because it uses the Atom Format, it can handle full length articles or even e-books. The term “micro” is quite misleading for such a powerful publishing tool.
A shift toward terms like “Storage” and “Publishing” would likely help developers see the true utility of these extensions.
A Note of Appreciation
A huge thank you to Schimon Jehudah for such an incredible learning session. Having a mentor who is willing to dive deep into the philosophy and “why” behind the technology makes a world of difference.
The clarity I gained from this meeting has already changed how I’m approaching my current projects. I’m incredibly grateful for the guidance and the expertise Schimon continues to share with me as I navigate the KDE community and open source development!