Do your sites open links in new windows by default?

I think is a good idea to open internal website links in the same page and external links (that point to any other domain ) in a new page/tab.

agreed with above comment.

Agreed with above too but the article may have changed my mind now.
Middle button click is quite helpful (didn't know about it).
But I'm never ever surprised and actually prefer it when external links open in new window. Its like you are reading a book with a quote + reference and then the full referred article appears in the middle of the book for 10 pages... Hard to come back to the actual content. Instead, if you are interested you go and get the referred book (similar to new window) then close it (close the new window) and get back to the page you were reading... Does it make any sense?

Any external links I have open in a new tab. All internal links open in the same window.

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I prefer linking to external sites with a new window.. all pages within my domain are the same window. This avoids the accidental clicking of the X to close the browser and subsequently the original page.

Agree with above comments. I think external links should be opened in separate windows.
One funny thing with this article is that it first says that it's good design to open links in same window because there are ways to work around it (with for example middle-click) and it's bad to open them in new windows because there is no way to work around it. And a bit later it gives a good example of how to do exactly this. Drag the link to the address bar.

And another funny thing is that the link "View Comments" that we clicked on to get here automatically opened a new tab... :-D