Preheat oven to 400 degrees. Line two sheet trays with silicone baking mats or lightly greased parchment paper.
In a medium saucepan, mix butter, sugar, salt and water. Bring to a boil and immediately remove from heat. Stir in flour and mix vigorously with a wooden spoon until the mixture is thick and well incorporated. Once slightly cooled, add eggs one at a time, beating well after each addition.
When all eggs are well incorporated, add the mixture to a 12-inch piping bag. Pipe 5-inch choux eclairs onto the prepared baking sheet. Bake for 10 minutes, then lower oven temperature to 325 degrees and bake 30 minutes more, until golden brown.