Sarah Richmond's translation makes an important contribution to Sartrean scholarship. L'Etre et le néant was first translated by Hazel Barnes in 1956 but it contained various errors. Richmond also had access to the internet and to Sartre's French and German sources. Her edition also contains an Introduction and a ‘Notes on the translation’ section.
Sartre published his work in 1943 and, unable to access all the works he cited, he often did so from memory. He also adopted certain translators’ neologisms: for example, Corbin's translation of Heidegger's Qu'est-ce que la métaphysique? , and when he quoted Nietzsche, he used two different translations, and he quotes Spinoza using a text by Hegel. He quotes a line from the playwright Beaumarchais without clarifying the context.
Sarah Richmond deals with many of these problems and also notes that the French gender system can be problematic. Also, Sartre's neologisms rendered finding English equivalents difficult. This is an excellent translation.