CREATE TABLE table_204_870 (id DECIMAL, "product" TEXT, "main functionality" TEXT, "input format" TEXT, "output format" TEXT, "platform" TEXT, "license and cost" TEXT, "notes" TEXT)

graphstream and egonet can be on any platform that supports what ?
SELECT "platform" FROM table_204_870 WHERE "product" = 'graphstream'
SELECT "platform" FROM "table_204_870" WHERE "product" = 'graphstream'