he last Service Release for Tekla Structures Tekla Structures can be used to interface with other existing applications, or solely as a platform to develop a customizable internal solution. It is an open solution that supports interoperability and standardization. Tekla Structures links with various systems through Tekla Open API™ application programming interface that is implemented using Microsoft® .NET technology. Examples of standard formats supported by Tekla Structures are IFC, CIS/2, SDNF and DSTV. Examples of proprietary formats supported by Tekla Structures are DWG, DXF and DGN.