The Word for World Is Forest (1972)
Ursula K. Le Guin (writer).
The Dispossessed (1974)
Part of the Hainish Cycle; the chronology is unclear.
The first anarcho-syndicalist utopia, and as such it is appropriately ambiguous, something the subtitle makes explicit.
References here: Always Coming Home (1985), The Prosperous Few and the Restless Many (1993), Worlds of Ursula K. Le Guin (2018).
Viewed 2019-02-21. Ugly in unsafe old browsers.