a writer or artist who sells services to different employers without a long-term contract with any of them - free lance- free lance- self employed person
a neutral or uncommitted person (especially in politics) - fencesitter
Adjective
not controlled by a party or interest group
(of a clause) capable of standing syntactically alone as a complete sentence "the main (or independent) clause in a complex sentence has at least a subject and a verb"
(of political bodies) not controlled by outside forces "an autonomous judiciary" "a sovereign state" - self governing
free from external control and constraint "an independent mind" "a series of independent judgments" "fiercely independent individualism"