The International Congress of Mathematicians is one of the world’s
premier forums for presenting and discussing new mathematical
discoveries. In 2018, it will be 121 years that have passed since the
first conference and Rio de Janeiro's turn to welcome participants
from around the world, in the 28th edition of the ICM.

The Organizing Committee has launched the "Open Arms program", which
offers 550 travel grants for mathematicians, young and senior, from
developing countries to attend the Congress.
http://www.icm2018.org/portal/en/travel-grants-program