Editing Stratus VOS (section)

===Programming for VOS===
VOS provides compilers for [[PL/I]], [[COBOL]], [[Pascal (programming language)|Pascal]], [[FORTRAN]], [[C (programming language)|C]] (with the [[VOS C]] and  [[GNU Compiler Collection|GCC]] compilers), and [[C++]] (also [[GNU Compiler Collection|GCC]]).<ref name="Vos Specifications">{{cite web|url=http://www.stratus.com/en/Products/VSeries-Continuum/OperatingSystems.aspx |title=Operating Systems |access-date=August 23, 2011 |url-status=dead |archive-url=https://web.archive.org/web/20110927111200/http://www.stratus.com/en/Products/VSeries-Continuum/OperatingSystems.aspx |archive-date=September 27, 2011 }}</ref>  Each of these programming languages can make VOS system calls (e.g. <code>s$seq_read</code> to read a record from a file), and has extensions to support varying-length strings in PL/I style. Developers typically code in their favourite VOS text editor, or offline, before compiling on the system; there are no VOS IDE applications.

In its history, Stratus has offered hardware platforms based on the [[Motorola 68000]] microprocessor family ("FT" and "XA" series), the [[Intel i860]] microprocessor family ("XA/R" series), the [[HP PA-RISC]] processor family ("Continuum" series), and the [[Intel Xeon]] [[x86]] processor family ("V Series").  All versions of VOS offer compilers targeted at the native instruction set, and some versions of VOS offer cross-compilers.

Stratus added support for the [[POSIX]] API in VOS Release 14.3 (on Continuum), and added support for the GNU C/C++ compiler, GNU gdb debugger, and many POSIX commands in VOS Release 14.4.  Each additional release of VOS has added more POSIX.1 capabilities, to the point where many user-mode open-source packages can now be successfully built. For this reason, beginning with Release 17.0, Stratus renamed VOS to OpenVOS.

Stratus offers supported ports of Samba, OpenSSL, OpenSSH, [[GNU Privacy Guard]], [[OpenLDAP]], [[Berkeley DB]], MySQL Community Server, Apache, [[IBM WebSphere MQ]], and many others.

Numeric values in VOS are always [[big endian]], regardless of the endianness of the underlying hardware platform.  On [[little endian]] servers with x86 processors, the compilers do a byte swap before reading or writing values to memory to transform the data to or from the native little endian format.