Lotus Development Corp is following up its plans for an IBM mainframe version of 1-2-3 with one for Unix: the new version will be developed alongside 1-2-3 Release 3.0 and will be optimised for use on a variety of workstations under System V, as well as supporting the forthcoming IEEE Posix Portable Operating System, and will comply with standards set forth by the X/Open consortium of Unix system vendors; Lotus says that it will also offer multi-tasking and multi-user capabilities for easy sharing of files and consolidating large spreadsheets and will support three-dimensional and linked worksheets; robust external data access; and the extended applications facility; although at the AT&T-Sun meet, it did not actually endorse Open Look.