On Stack Overflow, a programming forum, someone asked about how to create a new language using Unicode. It turns out that they were asking about Tigrinya, which is written using Ethiopic characters, and is already reasonably well supported (though input support is a little hit or miss and requires add-on software). But I took the opportunity to describe everything you need to support a new writing system on modern computers, along with references to how each of those components has already been implemented for the Ethiopic script and Tigrinya language.
I thought the conglangs group might be interest in this, as a reference for what you would need to do if you wanted to implement a new conscript. It's mostly a quick overview of all of the pieces, with lots of references to further information. It covers Unicode, UTF-8, creating fonts, briefly touches on advanced font and rendering support for cursive languages, embedding fonts in PDFs and web pages, entering Unicode codepoints in HTML, creating keyboards or input methods to type in a script directly, locales, and localization of software.
Hope this helps out anyone who wanted to try implementing a conscript on their computer, but didn't know where to start!