diff --git a/README.md b/README.md
index 52a22e0..1dcadc7 100644
--- a/README.md
+++ b/README.md
@@ -37,6 +37,8 @@ Steps:
   uninstall                    Remove build artifacts from prefix path
   c_app                        Run a C application built with Zig's build system.
   zig_app                      Run a Zig application linked to C source code.
+  c_app_with_static_lib        Run a C app linked to a c static lib all built with zig build. 
+  c_app_with_shared_lib        Run a C app linked to a c dynamic lib all built with zig build.  
   zmath_static                 Create a static library from C source code.
   zmath_shared                 Create a shared library from C source code.
   zig_app_shared               Run a Zig application that is linked to a shared library.
@@ -205,16 +207,16 @@ const std = @import("std");
 const zmath = @cImport(@cInclude("zmath.h"));
 
 pub fn main() !void {
-    const stdio = std.io.getStdOut().writer();
+    const stdio = std.fs.File.stdout.writerStreaming(.{});
 
     const a = 10;
     const b = 5;
 
     const resultAdd = zmath.add(a, b);
-    try stdio.print("{} + {} = {}\n", .{ a, b, resultAdd });
+    try stdio.interface.print("{} + {} = {}\n", .{ a, b, resultAdd });
 
     const resultSub = zmath.sub(a, b);
-    try stdio.print("{} - {} = {}\n", .{ a, b, resultSub });
+    try stdio.interface.print("{} - {} = {}\n", .{ a, b, resultSub });
 }
 ```
 
@@ -281,10 +283,12 @@ pub fn build(b: *std.Build) *std.Build.Step.Compile {
 
     lib.addIncludePath(b.path("include"));
     lib.addCSourceFiles(.{ .files = &[_][]const u8{"src/zmath.c"} });
-
+	
     lib.linkLibC();
 
     b.installArtifact(lib);
+    // return the lib to the caller so it can be passed in to the fn that builds apps
+    return lib;
 }
 ```
 
@@ -354,16 +358,16 @@ const std = @import("std");
 const zmath = @import("zmath.zig");
 
 pub fn main() !void {
-    const stdio = std.io.getStdOut().writer();
+    const stdio = std.fs.File.stdout.writerStreaming(.{});
 
     const a = 10;
     const b = 5;
 
     const resultAdd = try zmath.add(a, b);
-    try stdio.print("{d} + {d} = {d}\n", .{ a, b, resultAdd });
+    try stdio.interface.print("{d} + {d} = {d}\n", .{ a, b, resultAdd });
 
     const resultSub = try zmath.sub(a, b);
-    try stdio.print("{d} - {d} = {d}\n", .{ a, b, resultSub });
+    try stdio.interface.print("{d} - {d} = {d}\n", .{ a, b, resultSub });
 }
 ```
 
@@ -376,16 +380,18 @@ to link our application to our library.
 ```c
 const std = @import("std");
 
-pub fn build(b: *std.Build, target: std.Build.ResolvedTarget, optimize: std.builtin.OptimizeMode) *std.Build.Step.Compile {
+pub fn build(b: *std.Build, 
+	target: std.Build.ResolvedTarget, 
+	optimize: std.builtin.OptimizeMode,
+	lib: *std.Build.Step.Compile) *std.Build.Step.Compile {
     const exe = b.addExecutable(.{
         .name = "zig_app_shared",
         .root_source_file = b.path("src/zig_c_wrapper.zig"),
         .target = target,
         .optimize = optimize,
     });
-
-    exe.addObjectFile(b.path("zig-out/lib/zmath-shared.lib"));
-
+    // this avoids having to name the library file. Libraries are named very differently on Linux, Osx and Windows
+	exe.linkLibrary(lib)
     return exe;
 }
 ```
@@ -452,7 +458,13 @@ pub fn build(b: *std.Build) void {
     b.installArtifact(tests_exe);
 }
 ```
+## Two more pure 'C' examples
+Two additional 'C' examples have been provided to demonstrate how to use `zig build` to
+compile and link a 'C' program to a 'C' static or shared library. They are:
 
+-	`build_c_app_with_shared_lib` which builds an executable `c_app_with_shared_lib`, and
+- 	`build_c_app_with_static_lib` which builds an executable `c_app_with_static_lib`
+ 
 ## Resources
 - https://mtlynch.io/notes/zig-call-c-simple/
 What initially made me want to tackle this subject, this article is a great 
diff --git a/build.zig b/build.zig
index c9a653d..a8b0854 100644
--- a/build.zig
+++ b/build.zig
@@ -1,7 +1,10 @@
 const std = @import("std");
 
 const module_c_app = @import("build_c_app.zig");
-const module_zig_app = @import("build_zig_app.zig");
+const module_c_app_with_static_lib = @import("build_c_app_with_static_lib.zig");
+const module_c_app_with_shared_lib = @import("build_c_app_with_shared_lib.zig");
+
+const module_zig_call_c_app = @import("build_zig_call_c_app.zig");
 const module_lib_static = @import("build_c_static_lib.zig");
 const module_lib_shared = @import("build_c_shared_lib.zig");
 const module_zig_app_static = @import("build_zig_app_static.zig");
@@ -12,68 +15,72 @@ pub fn build(b: *std.Build) void {
     const target = b.standardTargetOptions(.{});
     const optimize = b.standardOptimizeOption(.{});
 
-    // c_app
-    const c_app = module_c_app.build(b, target, optimize);
-    const run_c_app = b.addRunArtifact(c_app);
-
-    b.installArtifact(c_app);
-
-    const run_c_app_step = b.step("c_app", "Run a C application built with Zig's build system.");
-    run_c_app_step.dependOn(&run_c_app.step);
-
-    // zig_app
-    const zig_app = module_zig_app.build(b, target, optimize);
-    const run_zig_app = b.addRunArtifact(zig_app);
-
-    b.installArtifact(zig_app);
-
-    const run_zig_app_step = b.step("zig_app", "Run a Zig application linked to C source code.");
-    run_zig_app_step.dependOn(&run_zig_app.step);
-
-    // zmath_static
+    // zmath lib static
     const lib_static = module_lib_static.build(b, target, optimize);
     const install_lib_static = b.addInstallArtifact(lib_static, .{});
-
     b.installArtifact(lib_static);
-
     const install_lib_static_step = b.step("zmath_static", "Create a static library from C source code.");
     install_lib_static_step.dependOn(&install_lib_static.step);
 
-    // zmath_shared
+    // zmath lib shared
     const lib_shared = module_lib_shared.build(b, target, optimize);
     const install_lib_shared = b.addInstallArtifact(lib_shared, .{});
-
     b.installArtifact(lib_shared);
-
     const install_lib_shared_step = b.step("zmath_shared", "Create a shared library from C source code.");
     install_lib_shared_step.dependOn(&install_lib_shared.step);
 
-    // zig_app_shared
-    const zig_app_shared = module_zig_app_shared.build(b, target, optimize);
-    const run_zig_app_shared = b.addInstallArtifact(zig_app_shared, .{});
+    // c_app - a c program linked with c object by compiling c_app.c and zmath.c
+    const c_app = module_c_app.build(b, target, optimize);
+    const run_c_app = b.addRunArtifact(c_app);
+    b.installArtifact(c_app);
+    const run_c_app_step = b.step("c_app", "Run a C application likned to otehr c objects.");
+    run_c_app_step.dependOn(&run_c_app.step);
 
-    b.installArtifact(zig_app_shared);
+    // c_app_with_static_lib - a c program linked against zmath static lib
+    const c_app_with_static_lib = module_c_app_with_static_lib.build(b, target, optimize, lib_static);
+    const run_c_app_with_static_lib = b.addRunArtifact(c_app_with_static_lib);
+    b.installArtifact(c_app_with_static_lib);
+    const run_c_app_with_static_lib_step = b.step("c_app_with_static_lib", "Run a C application linked to a c static lib all built with zig build.");
+    run_c_app_with_static_lib_step.dependOn(&run_c_app_with_static_lib.step);
+
+    // c_app_with_shared_lib - a c program compiled andlinked against zmath shared lib
+    const c_app_with_shared_lib = module_c_app_with_shared_lib.build(b, target, optimize, lib_shared);
+    const run_c_app_with_shared_lib = b.addRunArtifact(c_app_with_shared_lib);
+    b.installArtifact(c_app_with_shared_lib);
+    const run_c_app_with_shared_lib_step = b.step("c_app_with_shared_lib", "Run a C application linked to a c dynamic lib all built with zig build.");
+    run_c_app_with_shared_lib_step.dependOn(&run_c_app_with_shared_lib.step);
+
+    // zig_call_c_app - zig_call_c_app.zig is compiled with zmath.c and the 2 objects linked together
+    // zig_call_c_app explicitly imports zmath.c as a c module
+    const zig_call_c_app = module_zig_call_c_app.build(b, target, optimize);
+    const run_zig_call_c_app = b.addRunArtifact(zig_call_c_app);
+    b.installArtifact(zig_call_c_app);
+    const run_zig_app_step = b.step("zig_app", "Run a Zig application linked to C source code.");
+    run_zig_app_step.dependOn(&run_zig_call_c_app.step);
 
+    // zig_app_shared - zig_c_wrapped.zig calls zmath.zig which calls zmath_ext.zig which transforms the calls to c and then all
+    // that is liked with the static c library
+    const zig_app_shared = module_zig_app_shared.build(b, target, optimize, lib_shared);
+    const run_zig_app_shared = b.addInstallArtifact(zig_app_shared, .{});
+    b.installArtifact(zig_app_shared);
     const run_zig_app_shared_step = b.step("zig_app_shared", "Run a Zig application that is linked to a shared library.");
     run_zig_app_shared_step.dependOn(&install_lib_shared.step); // create and install shared library
     run_zig_app_shared_step.dependOn(&run_zig_app_shared.step);
 
-    // zig_app_static
-    const zig_app_static = module_zig_app_static.build(b, target, optimize);
+    // zig_app_static - zig_c_wrapped.zig calls zmath.zig which calls zmath_ext.zig which transforms the calls to c
+    // then all that is linked against the c shared library
+    const zig_app_static = module_zig_app_static.build(b, target, optimize, lib_static);
     const run_zig_app_static = b.addInstallArtifact(zig_app_static, .{});
-
     b.installArtifact(zig_app_static);
-
     const run_zig_app_static_step = b.step("zig_app_static", "Run a Zig application that is linked to a static library.");
     run_zig_app_static_step.dependOn(&install_lib_static.step); // create and install static library
     run_zig_app_static_step.dependOn(&run_zig_app_static.step);
 
-    // tests
+    // // tests
     const tests = module_tests.build(b, target, optimize);
     const run_tests = b.addRunArtifact(tests);
-
     b.installArtifact(tests);
-
     const run_tests_step = b.step("tests", "Run a Zig tests of C source code.");
     run_tests_step.dependOn(&run_tests.step);
 }
+//
diff --git a/build_c_app.zig b/build_c_app.zig
index f28b926..593439b 100644
--- a/build_c_app.zig
+++ b/build_c_app.zig
@@ -1,15 +1,13 @@
 const std = @import("std");
 
 pub fn build(b: *std.Build, target: std.Build.ResolvedTarget, optimize: std.builtin.OptimizeMode) *std.Build.Step.Compile {
-    const exe = b.addExecutable(.{
-        .name = "c_app",
+    const exe = b.addExecutable(.{ .name = "c_app", .root_module = b.createModule(.{
         .target = target,
         .optimize = optimize,
-    });
+    }) });
 
     exe.addIncludePath(b.path("include"));
     exe.addCSourceFiles(.{ .files = &[_][]const u8{ "src/c_app.c", "src/zmath.c" } });
-
     exe.linkLibC();
 
     return exe;
diff --git a/build_c_app_with_shared_lib.zig b/build_c_app_with_shared_lib.zig
new file mode 100644
index 0000000..3bc88e2
--- /dev/null
+++ b/build_c_app_with_shared_lib.zig
@@ -0,0 +1,15 @@
+const std = @import("std");
+
+pub fn build(b: *std.Build, target: std.Build.ResolvedTarget, optimize: std.builtin.OptimizeMode, lib: *std.Build.Step.Compile) *std.Build.Step.Compile {
+    const exe = b.addExecutable(.{ .name = "c_app_with_shared_lib", .root_module = b.createModule(.{
+        .target = target,
+        .optimize = optimize,
+    }) });
+
+    exe.addIncludePath(b.path("include"));
+    exe.addCSourceFiles(.{ .files = &[_][]const u8{"src/c_app.c"} }); //, "src/zmath.c" } });
+    exe.linkLibrary(lib);
+    exe.linkLibC();
+
+    return exe;
+}
diff --git a/build_c_app_with_static_lib.zig b/build_c_app_with_static_lib.zig
new file mode 100644
index 0000000..4ee3608
--- /dev/null
+++ b/build_c_app_with_static_lib.zig
@@ -0,0 +1,15 @@
+const std = @import("std");
+
+pub fn build(b: *std.Build, target: std.Build.ResolvedTarget, optimize: std.builtin.OptimizeMode, lib: *std.Build.Step.Compile) *std.Build.Step.Compile {
+    const exe = b.addExecutable(.{ .name = "c_app_with_static_lib", .root_module = b.createModule(.{
+        .target = target,
+        .optimize = optimize,
+    }) });
+
+    exe.addIncludePath(b.path("include"));
+    exe.addCSourceFiles(.{ .files = &[_][]const u8{"src/c_app.c"} }); //, "src/zmath.c" } });
+    exe.linkLibrary(lib);
+    exe.linkLibC();
+
+    return exe;
+}
diff --git a/build_c_shared_lib.zig b/build_c_shared_lib.zig
index c2a64b0..366f2ef 100644
--- a/build_c_shared_lib.zig
+++ b/build_c_shared_lib.zig
@@ -1,11 +1,10 @@
 const std = @import("std");
 
 pub fn build(b: *std.Build, target: std.Build.ResolvedTarget, optimize: std.builtin.OptimizeMode) *std.Build.Step.Compile {
-    const lib = b.addSharedLibrary(.{
-        .name = "zmath-shared",
+    const lib = b.addLibrary(.{ .linkage = .dynamic, .name = "zmath-shared", .root_module = b.createModule(.{
         .target = target,
         .optimize = optimize,
-    });
+    }) });
 
     lib.addIncludePath(b.path("include"));
     lib.addCSourceFiles(.{ .files = &[_][]const u8{"src/zmath.c"} });
diff --git a/build_c_static_lib.zig b/build_c_static_lib.zig
index 7610f3c..13afbb5 100644
--- a/build_c_static_lib.zig
+++ b/build_c_static_lib.zig
@@ -1,16 +1,17 @@
 const std = @import("std");
 
 pub fn build(b: *std.Build, target: std.Build.ResolvedTarget, optimize: std.builtin.OptimizeMode) *std.Build.Step.Compile {
-    const lib = b.addStaticLibrary(.{
-        .name = "zmath-static",
+    const lib = b.addLibrary(.{ .linkage = .static, .name = "zmath-static", .root_module = b.createModule(.{
         .target = target,
         .optimize = optimize,
-    });
+    }) });
 
     lib.addIncludePath(b.path("include"));
     lib.addCSourceFiles(.{ .files = &[_][]const u8{"src/zmath.c"} });
 
     lib.linkLibC();
+    var stdio = std.fs.File.stdout().writerStreaming(&.{});
 
+    stdio.interface.print("\nXXBuild static library name {s}. \n", .{lib.out_lib_filename}) catch {};
     return lib;
 }
diff --git a/build_test_zmath.zig b/build_test_zmath.zig
index dd39d62..19e8b86 100644
--- a/build_test_zmath.zig
+++ b/build_test_zmath.zig
@@ -1,12 +1,11 @@
 const std = @import("std");
 
 pub fn build(b: *std.Build, target: std.Build.ResolvedTarget, optimize: std.builtin.OptimizeMode) *std.Build.Step.Compile {
-    const exe = b.addTest(.{
-        .name = "test_zmath",
+    const exe = b.addTest(.{ .name = "test_zmath", .root_module = b.createModule(.{
         .root_source_file = b.path("tests/test_zmath.zig"),
         .target = target,
         .optimize = optimize,
-    });
+    }) });
 
     exe.addIncludePath(b.path("include"));
     exe.addCSourceFile(.{
diff --git a/build_zig_app_shared.zig b/build_zig_app_shared.zig
index 93ecaa3..1a1fad5 100644
--- a/build_zig_app_shared.zig
+++ b/build_zig_app_shared.zig
@@ -1,14 +1,15 @@
 const std = @import("std");
 
-pub fn build(b: *std.Build, target: std.Build.ResolvedTarget, optimize: std.builtin.OptimizeMode) *std.Build.Step.Compile {
-    const exe = b.addExecutable(.{
-        .name = "zig_app_shared",
+pub fn build(b: *std.Build, target: std.Build.ResolvedTarget, optimize: std.builtin.OptimizeMode, lib: *std.Build.Step.Compile) *std.Build.Step.Compile {
+    const exe = b.addExecutable(.{ .name = "zig_app_shared", .root_module = b.createModule(.{
         .root_source_file = b.path("src/zig_c_wrapper.zig"),
         .target = target,
         .optimize = optimize,
-    });
+    }) });
 
-    exe.addObjectFile(b.path("zig-out/lib/zmath-shared.lib"));
+    // exe.addObjectFile(b.path("zig-out/lib/libzmath-shared.dylib"));
+    exe.linkLibrary(lib);
+    // exe.addRPath(b.path("zig-out/lib"));
 
     return exe;
 }
diff --git a/build_zig_app_static.zig b/build_zig_app_static.zig
index 870fba4..00f673a 100644
--- a/build_zig_app_static.zig
+++ b/build_zig_app_static.zig
@@ -1,14 +1,13 @@
 const std = @import("std");
 
-pub fn build(b: *std.Build, target: std.Build.ResolvedTarget, optimize: std.builtin.OptimizeMode) *std.Build.Step.Compile {
-    const exe = b.addExecutable(.{
-        .name = "zig_app_static",
+pub fn build(b: *std.Build, target: std.Build.ResolvedTarget, optimize: std.builtin.OptimizeMode, lib: *std.Build.Step.Compile) *std.Build.Step.Compile {
+    const exe = b.addExecutable(.{ .name = "zig_app_static", .root_module = b.createModule(.{
         .root_source_file = b.path("src/zig_c_wrapper.zig"),
         .target = target,
         .optimize = optimize,
-    });
-
-    exe.addObjectFile(b.path("zig-out/lib/zmath-static.lib"));
+    }) });
 
+    // exe.addObjectFile(b.path("zig-out/lib/libzmath-static.a"));
+    exe.linkLibrary(lib);
     return exe;
 }
diff --git a/build_zig_call_c_app.zig b/build_zig_call_c_app.zig
new file mode 100644
index 0000000..c8b04fc
--- /dev/null
+++ b/build_zig_call_c_app.zig
@@ -0,0 +1,18 @@
+const std = @import("std");
+
+pub fn build(b: *std.Build, target: std.Build.ResolvedTarget, optimize: std.builtin.OptimizeMode) *std.Build.Step.Compile {
+    const exe = b.addExecutable(.{ .name = "zig_call_c_app", .root_module = b.createModule(.{
+        .root_source_file = b.path("src/zig_call_c_app.zig"),
+        .target = target,
+        .optimize = optimize,
+    }) });
+
+    exe.addIncludePath(b.path("include"));
+    exe.addCSourceFile(.{
+        .file = b.path("src/zmath.c"),
+    });
+
+    exe.linkLibC();
+
+    return exe;
+}
diff --git a/src/zig_app.zig b/src/zig_app.zig
deleted file mode 100644
index 08a3c65..0000000
--- a/src/zig_app.zig
+++ /dev/null
@@ -1,15 +0,0 @@
-const std = @import("std");
-const zmath = @cImport(@cInclude("zmath.h"));
-
-pub fn main() !void {
-    const stdio = std.io.getStdOut().writer();
-
-    const a = 10;
-    const b = 5;
-
-    const resultAdd = zmath.add(a, b);
-    try stdio.print("{} + {} = {}\n", .{ a, b, resultAdd });
-
-    const resultSub = zmath.sub(a, b);
-    try stdio.print("{} - {} = {}\n", .{ a, b, resultSub });
-}
diff --git a/src/zig_c_wrapper.zig b/src/zig_c_wrapper.zig
index 2a627ec..2286251 100644
--- a/src/zig_c_wrapper.zig
+++ b/src/zig_c_wrapper.zig
@@ -2,14 +2,14 @@ const std = @import("std");
 const zmath = @import("zmath.zig");
 
 pub fn main() !void {
-    const stdio = std.io.getStdOut().writer();
-
+    var stdio = std.fs.File.stdout().writerStreaming(&.{});
+    try stdio.interface.print("Hello this is zig_wrappper \n", .{});
     const a = 10;
     const b = 5;
 
     const resultAdd = try zmath.add(a, b);
-    try stdio.print("{d} + {d} = {d}\n", .{ a, b, resultAdd });
+    try stdio.interface.print("{d} + {d} = {d}\n", .{ a, b, resultAdd });
 
     const resultSub = try zmath.sub(a, b);
-    try stdio.print("{d} - {d} = {d}\n", .{ a, b, resultSub });
+    try stdio.interface.print("{d} - {d} = {d}\n", .{ a, b, resultSub });
 }
diff --git a/src/zig_call_c_app.zig b/src/zig_call_c_app.zig
new file mode 100644
index 0000000..91048c4
--- /dev/null
+++ b/src/zig_call_c_app.zig
@@ -0,0 +1,16 @@
+const std = @import("std");
+const zmath = @cImport(@cInclude("zmath.h"));
+
+pub fn main() !void {
+    // const stdio = std.io.getStdOut().writer();
+    var stdio = std.fs.File.stdout().writerStreaming(&.{});
+    try stdio.interface.print("zig_call_c_app.zig .. calls zmath.c \n", .{});
+    const a = 10;
+    const b = 5;
+
+    const resultAdd = zmath.add(a, b);
+    try stdio.interface.print("{} + {} = {}\n", .{ a, b, resultAdd });
+
+    const resultSub = zmath.sub(a, b);
+    try stdio.interface.print("{} - {} = {}\n", .{ a, b, resultSub });
+}
diff --git a/src/zmath.c b/src/zmath.c
index e98ef0f..7df0487 100644
--- a/src/zmath.c
+++ b/src/zmath.c
@@ -1,9 +1,11 @@
 #include "zmath.h"
-
+#include <stdio.h>
 int add(int a, int b) {
+    printf("zmath.c add a: %d b: %d\n", a, b);
     return a + b;
 }
 
 int sub(int a, int b) {
+    printf("zmath.c sub a: %d b: %d\n", a, b);
     return a - b;
 }
diff --git a/src/zmath_ext.zig b/src/zmath_ext.zig
index 0704c83..5101c0d 100644
--- a/src/zmath_ext.zig
+++ b/src/zmath_ext.zig
@@ -1,4 +1,5 @@
+const builtin = @import("builtin");
 const zmath_h = @cImport(@cInclude("zmath.h"));
 
-pub extern fn add(a: c_int, b: c_int) callconv(.C) c_int;
-pub extern fn sub(a: c_int, b: c_int) callconv(.C) c_int;
+pub extern fn add(a: c_int, b: c_int) callconv(.c) c_int;
+pub extern fn sub(a: c_int, b: c_int) callconv(.c) c_int;