In this article I'll describe my personal view on the next 10 years. Please be kind if you compare my predictions in 10 years' time with the actual situation.... Things always tend to work out differently, and I have not been able to use my crystal ball because it is still in repair... :-)
The last few years there has been a shift from desktop PCs to mobile devices. Recently there has been a boost in responsive templates that adapt the websites screen size to the device. That way the website is better visible on a mobile device. Furthermore, mobile websites have a better ranking on search engines, especially when doing the search on a mobile device. This will further increase the demand for mobile websites.
However, with responsive templates the amount of data that is transferred to the device is still the same. That's not good if you have to pay for your mobile data use. What if you only transfer the essential data?
It's estimated that 40% of the total world population use the internet and 70% use mobile phones. Last year smart phone subscriptions in India, Brazil & China grew double figures. When internet use further increases in those countries, local content will also be more popular. The demand for CMS platforms will grow, especially the ones that have language packs & documentation in those languages and that are backed by local communities. Existing websites might want to broaden their target audience to other countries & languages, which will raise the demand for multilingual websites.
Structured Data in HTML
Currently an HTML web-page is unstructured data with some mark-up to create a nice layout. It's difficult for search engines like Google to interpret the context of your data. Rich Snippets or Microdata is a method to create context in HTML pages so that search engines better index your site. There are already a lot of snippet structure models available at http://schema.org/
Application Programming Interface (API)
To make structured data from a database available it's necessary to create an interface to that data. With the API documentation programmers can create phone and web-applications that communicate to your database via your API. If you want to make changes in your database, it's possible to do so without changing the API. A change should not break the external applications that use your API.
Web services are a way to interact with a website via http to exchange structured data. That way the data can be reused by other other websites, mobile Apps, etc. Web services only transfer data (no HTML mark-up). The data is structured, and the web service is managed via an API.
For example: Someone that uses a browser to find a place on Google Maps will get an HTML page with a map. An application that calls the Google Map API with some address, will only get structured data back (e.g. the coordinates of that location).
Data storage is still getting cheaper so there's no real need to delete old data. Besides, data can be valuable because you can analyse it to find trends that businesses can use marketing-wise. Even more, if you combine your data with other sources then you might be able to analyse more trends. What's the best way to combine data from other sources?
Open source software is an excellent way to use collective resources to develop & maintain software. Sharing knowledge & resources improves the software considerably. This concept of working together and sharing information is also used with sharing data. In the openstreetmap.org community users collect local data about streets and share via the website. Governments collect, store and process large amounts of data. Some general data can be valuable for other people. Because it has already been paid for with tax money, more and more governments make their data available as open data.
Open Data is structured. However, how do all the fields of data relate to each other? Tim Berners-Lee, the inventor of the World Wide Web, came up with a way to describe the relations between the structured data fields: Linked Data. With Linked Data you give context to your data. JSON-LD is such a format.
There will be a shift in sharing information via HTML web pages to linked structured data exchange via (web) applications.
Further hardware miniaturization
Computers are still getting smaller. The popularity of the Raspberry Pi shows that there's demand for mini computers that can be used for education, domotica and hardware projects. Wearable Technology, clothing and accessories that have mini computers inside, are becoming popular. Think about the smart watch which functions as an interface to a smart phone. I run Joomla on a Raspberry Pi but do not see any use (yet) for running Joomla on my watch or smart phone. However, all those small devices will share data via the internet (of things)….
Connecting devices & "Internet of Things
More and more devices can connect to the internet. They use the internet to autonomously retrieve information from other sources, give information to other sources, make it possible to manage the device over the network and (auto)update their firmware (the software on their microchip).
This trend is called "Internet of Things" (IoT). Large companies add this connectivity to their devices. Recently a device called ESP8266 came onto the market: a 5 dollar self-contained Wi-Fi network solution that makes it possible (for hobbyists) to connect devices to the internet via Wi-Fi. Websites might function as data containers that retrieve data from IoT devices.
The benefit of IoT is that you can share data autonomously & manage devices more easily. The down-side is that there's currently no universal language or protocol. And it can raise privacy issues and security issues.
In 2025 Joomla will still be a CMS to build websites that you can visit with a browser. However, the users will increasingly use a mobile phone to browse your website. And besides presenting HTML documents to visitors like a Joomla website currently does, it will share data via web services with other web or mobile phone applications and IoT devices.
An open source project like Joomla is driven by a community. I hope that the Joomla community will continue to grow, especially in the emerging markets. I believe that the community will further improve the User Experience (UX) and Accessibility of Joomla, and integrate useful technological trends into Joomla.