Do I Still Need to Include Type="Value" in HTML5

Do I still need to include type=value in HTML5?

It's not needed in HTML5 but in HTML<=4 or XHTML it's required.

Is type=text/css necessary in a link tag?

It's not required with the HTML5 spec, but for older versions of HTML is it required.

Html 4 W3.org spec

http://www.w3.org/TR/html40/struct/links.html#edef-LINK
http://www.w3.org/TR/html40/present/styles.html

Type stands for The MIME type of the style sheet. The only supported value I have ever seen is Text/CSS, which is probably why HTML5 has dropped it. I imagine they had it for earlier versions to allow future expansion possibilities which never happened.

Using HTML5 and not specifying the type, I have run so far into no problems with compatibility even when testing older versions of IE.

Is the 'type' attribute necessary for script tags?

For HTML 4.x, the type attribute is required. Source

This attribute specifies the scripting language of the element's contents and overrides the default scripting language. The scripting language is specified as a content type (e.g., "text/javascript"). Authors must supply a value for this attribute. There is no default value for this attribute.

For HTML 5, it is optional. If it is not specified, it defaults to text/javascript. Source

The type attribute gives the language of the script or format of the data. If the attribute is present, its value must be a valid MIME type. The charset parameter must not be specified. The default, which is used if the attribute is absent, is "text/javascript".

Recommendation: See HTML 5.2

For HTML 5.2, it should be omitted if using a valid JavaScript MIME type (e.g. text/javascript). Source

Omitting the attribute, or setting it to a JavaScript MIME type, means that the script is a classic script, to be interpreted according to the JavaScript Script top-level production. Classic scripts are affected by the charset, async, and defer attributes. Authors should omit the attribute, instead of redundantly giving a JavaScript MIME type.

Do we need type=text/css for link in HTML5

The HTML5 spec says that the type attribute is purely advisory and explains in detail how browsers should act if it's omitted (too much to quote here). It doesn't explicitly say that an omitted type attribute is either valid or invalid, but you can safely omit it knowing that browsers will still react as you expect.

Do you need text/javascript specified in your script tags?

See Crockford's write-up on the <script> tag, most notably:

Do not use the <!-- //--> hack with scripts. It was intended to prevent scripts from showing up as text on the first generation browsers Netscape 1 and Mosaic. It has not been necessary for many years. <!-- //--> is supposed to signal an HTML comment. Comments should be ignored, not compiled and executed. Also, HTML comments are not to include --, so a script that decrements has an HTML error.

...

type="text/javascript"

This attribute is optional. Since Netscape 2, the default programming language in all browsers has been JavaScript. In XHTML, this attribute is required and unnecessary. In HTML, it is better to leave it out. The browser knows what to do.

Is there a float input type in HTML5?

The number type has a step value controlling which numbers are valid (along with max and min), which defaults to 1. This value is also used by implementations for the stepper buttons (i.e. pressing up increases by step).

Simply change this value to whatever is appropriate. For money, two decimal places are probably expected:

<label for="totalAmt">Total Amount</label>
<input type="number" step="0.01" id="totalAmt">

(I'd also set min=0 if it can only be positive)

If you'd prefer to allow any number of decimal places, you can use step="any" (though for currencies, I'd recommend sticking to 0.01). In Chrome & Firefox, the stepper buttons will increment / decrement by 1 when using any. (thanks to Michal Stefanow's answer for pointing out any, and see the relevant spec here)

Here's a playground showing how various steps affect various input types:

<form>
  <input type=number step=1 /> Step 1 (default)<br />
  <input type=number step=0.01 /> Step 0.01<br />
  <input type=number step=any /> Step any<br />
  <input type=range step=20 /> Step 20<br />
  <input type=datetime-local step=60 /> Step 60 (default)<br />
  <input type=datetime-local step=1 /> Step 1<br />
  <input type=datetime-local step=any /> Step any<br />
  <input type=datetime-local step=0.001 /> Step 0.001<br />
  <input type=datetime-local step=3600 /> Step 3600 (1 hour)<br />
  <input type=datetime-local step=86400 /> Step 86400 (1 day)<br />
  <input type=datetime-local step=70 /> Step 70 (1 min, 10 sec)<br />
</form>

<script src=yourpath.js></script>