The Gobo Eiffel Structure Library is a portable Eiffel class library covering data structures and algorithms. When this library has been developed, there was no data structure library standard, and no portable library was publicly available. Each Eiffel compiler provides its own data structure library, but none of them is portable (see portability issues). This library has hence been developed as a foundation for other portable libraries provided in the Gobo Eiffel Project. The Gobo Eiffel Structure Library contains the classic containers needed in everyday programming, such as lists, stacks or tables, and provides different implementations such as linked, bilinked, arrayed, multiarrayed or hashed. More data structures may be added in the future if there is a need for them. There is nothing really new in this library. Most of the ideas come from other existing data structure libraries.