I have a few suggestions regarding the layout of the ufopedia (as of V2.0-RC5). I understand that some of these ideas require extensive coding, ...these are meant for future versions of UFO:AI.
1) Navigation:
I suggest that each chapter has a seperate table of contents. That way the player can quickly navigate to a specific item. Right now you have to go through all aritcles sequentially and usually the most recently reseached ones are at the end (-> a lot of clicking).
2) Layout of item description:
The item descriptions as shown in the wiki are quite long, lots of text to read. So first of all, we will need a scrollable text view. To present more text at the first glance, I suggest to use the full vertical screen size for the text and move the stats and requirements subwindows to the right, just below the item picture. The requirements need far less space than they have now.
The perfect layout would also have a tree-view to the left, showing the ufopedia TOC/sub-TOCs. But this is probably a lot of work.
3) Usability:
What's the point of the ufopedia? You have researched some new technology or weapon and want to see what it can do and whether it's worth to manufacture or buy the new weapon. To do this you have to compare it the existing ones, and this is very difficult now. Is it worth to switch to the Plasma Rifle or should I stick with the Laser Rifle? Right now this means you have to click through a lot of pages trying to remember how many TUs the primary shot of the the Plasma Rifle costs...then the same for the damage..etc. Basically you end up writing it down on paper.
You already know, what I am going to suggest: we need a way to compare stuff in the ufopedia. There are two options:
a) Make a table showing all (known) weapons and all stats at one glance.
b) Reserve a small area in the article page for display of a "reference" weapon. This small area would only show the stats and a small picture of the weapon.
Personally, I like version a) more. Otherwise people are going to create web pages with this kind of information. This would spoil the game for players who have not yet researched the whole tree.
Right now the use of the ufopedia is very frustrating and I am actually using the Buy/Sell screen to compare weapon stats. But there the description is not available...