The U.S. State Department, Office of the Historian has an article on this.

Here's a frontpage of Finnish newspaper from the city of Oulu:

http://digi.kansalliskirjasto.fi/sanomalehti/binding/411718

It says that the World and the America has lost a great man. There's a detailed biography of him. They quote his speech and hope that his death do not hinder the great future of the USA.

A fennoman magazine Suometar:

"He wanted to spread freedom and equality for those who against the principles of the Christianity and modern sense of justice are still used as objects of ill-gained wealth"

"We honor Lincoln not only the abolishment of the slavery, but a genuine representative of the true democracy"

"For the work that he has done, he has eternally earned his place on the mankind's history"

"While we don't know yet the concequences of this horrible, despicable deed, we are assured that there will be no lack of men in the USA who will continue his work"

It's not about the assassination itself but for those who haven't read this already I think this short bit by Tolstoy is the sort of thing most people with an interest in history can appreciate. http://www.loa.org/images/pdf/Tolstoy_on_Lincoln.pdf

I don't know that this is up to snuff for this sub reddit, but this article might be of some use. This NPR article contains some responses from foreign governments.

I'm hoping and searching for more information such as posted by /u/wstd