A ringworld in Elf Sternberg's The Journal Entries of Kennet R'yal Shardik, et. al., and Related Tales.
Pendor, a ringworld circling the star Pin, has a radius of approximately 1AU and a surface area approximately three million times that of earth (3,000,000 terrs). It's day cycle is created by a ring of shadow squares which orbit just slightly inside it. On the sun-side the squares are giant solar panels, producing incomprehensible amounts of energy. The ring is inhabited by several sentient species.
The ring itself is identical to Niven's, with the following changes:
1. the shadow ring is moved outwards to the point where is only a few dosen edge wall heights up from the surface
2. The empty sections in the shadow ring are replaced with refractive panels to cause some solar movement during the day and two flashes at sunwax and sunwane where the sun grows and shrinks in visual size very rapidly.
3. geological features are solid and formed by movement of plates.
4. A planet (Pandora) is added a bit inside the shadow squares to create some oceanic flow on the ring.
5. No maglev transportation around the ring, SDisks are relied on instead.
Other than that its pretty much identical to the Ringworld.
See Also: Pendorian Calendar, Pendorian Time, Pin System