Does a meta tag for "og:title" make redundant a meta tag for "title"?

My site has these two meta tags which currently have the same value:

<meta name="title" content="My Title" />    
<meta property="og:title" 开发者_开发知识库 name="title" content="My Title" />

The second one is a format required for facebook connectivity.

Does this mean the first one is redundant and can be removed?

It's best to have both tags present. The tag tells Search engines about your page for indexing and also shows up as the title in SERPs. The og:title tag helps Facebook index content so your page can feature in-Facebook search results and also for defined content when that particular URL on your website is shared. Also helps to add the og:image attribute which is the preview image on standard Facebook posts/shares.

Also, there is no

<meta name="title". 

It's

<title> ......... </title>

No. The Facebook meta tag is not standard and you should not expect anyone else besides Facebook to use the value of that tag for anything.

The first one is the standard title tag, which is usually same as the page title. It is (or atleast was) used by search engines. See this.

I have been able to find no official reference which describes the first tag: <meta name="title" content="My Title" />. In practice, it seems to be of no use and if it ever was of use, I suspect it was just a lazy parser in a web crawler.

The second tag is of use. The OpenGraph standard is used for sharing by many sites other than Facebook. While it won't help search rankings directly, it may help indirectly by way of more attractive, better-formatted shares.

I'd suggest using more OpenGraph tags than just the og:title. Others, including og:image will help make better shares.

Because your second meta tag also includes the name attribute any compliant parser should pick it up for the title. Therefore your first meta tag is redundant.

I don't know any system that uses the title meta tag though.