openua aims to become an open-source implementation of (one of the smaller profiles of) the OPC UA binary protocol. openua is written in Ada (2012). This has the following advantages:

• Fast
• Can be linked with C-code (and interfaced to many other languages)
• Multi-plattform code (Win/Linux/Embedded, big & small-endian)
• No buffer overflows and no memory leaks (you can have those, but it is way easier to write safe code than in C)
• Built-in support for parallelism/concurrency
• Can be certified for high-risk applications (e.g. EAL)

Currently, openua supports only reading/writing (all) data types defined in the UA standard from/to a binary stream. This includes handling of arrays and variable-size objects in a memory-safe way.

Create some UA built-in types and stream them to stdout

with Ada.Text_IO.Text_Streams; use Ada.Text_IO; 
with Types.Builtin; use Types.Builtin;

procedure Test_Types is
   TestNode : constant NodeId := (FOURBYTE_NODEID, Byte'Val(1), 5);
   TestNullString : constant Types.Builtin.String := Types.Builtin.String'(Create(null));
begin
   Binary_Write(Text_Streams.Stream (Current_Output), TestNode);
   Binary_Write(Text_Streams.Stream (Current_Output), TestNullString);
end Test_Types;