< background: -o-linear-gradient(#FFB260, #FF7F13); --- > background: -o-linear-gradient(#FFB260, #FF3F13);
Programmers find this a great convenience: the tools they use to manage source code, including construction of validated production versions, extend more naturally to the graphical constructs of Web design.
This advantage amplifies even more for opacity and other CSS3 markups. Suppose a company, "Acme Widgets", styled its own name with opacity on its home page. Before CSS3, this was done with Photoshop or a similar tool, and resulted in an image which displayed the words "Acme Widgets" with a specific opacity.
However bold the graphics, the content was totally lost to search engines. Because they're embedded in an image, the words "Acme Widgets" are effectively invisible to search engines. In the early years of search engines, there were several famous cases of important Web pages not showing up in search results precisely because the search engines saw much less textual content than human readers did.
CSS3 change this. CSS3 makes it possible to maintain far more of the textual content of a page as text, yet still style it for opacity, 2-D and 3-D effects, and so on. The implications for SEO are enough in themselves to make CSS3 compelling: the beauty of your Web pages doesn't matter at all when no one sees them, and older styles of graphical implementation make too much of your content invisible for search engines and the prospective visitors who use them.
3. Sophisticated animation effects
HTML5 is full of individual features with the characteristics already explained above: HTML5 gives the same appearance the top Web designers were already achieving, but at less expense, with quicker load-times, and the SEO and maintenance advantages of semantic markup. HTML5 also introduces effects that were generally beyond earlier versions of the standard; one of these is animation.
For sophisticated animation effects, Web teams in the past have generally turned to Flash. Flash has well-known disadvantages: search engines don't index it (not strictly true, but certainly a liability at best), Apple's iOS and other operating systems don't allow it, and its security profile and licensing restrict its use in many organizations. With HTML5, though, relatively sophisticated visual animations become available as semantic animations.
4. Easier Web app development, especially for mobile apps
A final qualitative advantage that HTML5 offers is that it's rich enough as a programming environment to compete with native applications. This is particularly important, again, for mobile end-users. Native app development is costly: its programmers are expensive, licensing ranges between whimsical and frustrating, and portability is a challenge. HTML5 is so potent that many applications can effectively be coded entirely within HTML5. Consider the advantages over native apps:
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