Theme development

Is it possible to run two different versions of the same base-theme in a multi-site environment, keeping both base-themes readily updatable?

The reason we need to do this is we would like to make the switch from Omega 3 to Omega 4 but have a fair few sites running subthemes based on Omega 3.

All suggestions are greatly appreciated!

I have three views from my blog on my front page. First hold the most recent, the second the most viewed and the last top rated posts.

I want to have Liquid Slider (http://liquidslider.com/) animate this views such that the tabs will be labeled Most Viewed, Top Rated and Most Recent and when you click on any of the tabs the corresponding view slides in.

I've done a lot more reading and I'm bringing myself up to speed from knowing nothing to having a grasp of things. But recently I've been toying with the CSS files for Commerce Kickstarter to simply change some colors around, and so forth.
My question is should I make a subtheme for such trivial changes?

I'm very new to theme development, I'm working through an interesting problem at the moment and I wanted to make sure I'm going in the right direction and not picking up any bad practices.

I want to output a menu block in the same div area as the body field from the node which is rendering. The other fields on the page should output lower down the page, outside this div, using the regular render function.

Hi guys,
I'm trying to insert some video files into my site. I'm not too familiar with the protocol, but what I want to achieve is to be able to add html5 tags to, let's say, a node, and have that video displayed to the visitors. I have tried many modules and libraries, but so far nothing did the trick.
If I add the tags to a full html post all I get is the code as text without being rendered into video. I know I'm doing at least something right, because when I add my code to the user end on element inspector in chrome, I get the video no problems.

Hello and Happy Thursday!

I would like to know if it is possible to create a search bar (to search a database of news articles and books) on my site. I would like this search bar to also search within the site. So the user could either bubble database of books or site as their option. Yes, I am aware that you can include the search block - but I want to have a multi-function search box that is customed built.

Currently, our site has the abilty to search news articles and books. However, if a customer wanted to search the site, they would so not be able to!