Preheat oven to 425°F (220°C). In a saucepan, bring water and butter to a boil. Remove from heat, add flour, and stir until mixture forms a ball. Let cool for 5 minutes.
Add eggs one at a time, beating well after each addition. Transfer dough to a piping bag and pipe 4-inch strips onto a baking sheet.
Bake for 20 minutes or until golden brown. Let cool completely.
For the filling, whip heavy cream, sugar, and vanilla until stiff peaks form. Fill eclairs with cream using a piping bag.
For the glaze, heat chocolate and cream in a saucepan over low heat until smooth. Dip tops of eclairs in glaze and let set.