diff --git a/openfpga/src/base/openfpga_context.h b/openfpga/src/base/openfpga_context.h
new file mode 100644
index 000000000..a0e6272ff
--- /dev/null
+++ b/openfpga/src/base/openfpga_context.h
@@ -0,0 +1,35 @@
+#ifndef OPENFPGA_CONTEXT_H
+#define OPENFPGA_CONTEXT_H
+
+#include "openfpga_arch.h"
+
+/********************************************************************
+ * This file includes the declaration of the date structure 
+ * OpenfpgaContext, which is used for data exchange between 
+ * different modules in OpenFPGA shell environment 
+ *
+ * If a command of OpenFPGA needs to exchange data with other commands,
+ * it must use this data structure to access/mutate.
+ * In such case, you must add data structures to OpenfpgaContext
+ *
+ * Note:
+ * Please respect to the following rules when using the OpenfpgaContext
+ * 1. This data structure will be created only once in the main() function
+ *    The data structure is design to be large and contain all the 
+ *    data structure required by each module of OpenFPGA core engine.
+ *    Do NOT create or duplicate in your own module!     
+ * 2. Be clear in your mind if you want to access/mutate the data inside OpenfpgaContext
+ *    Read-only data should be accessed by 
+ *      const OpenfpgaContext& 
+ *    Mutate should use reference
+ *      OpenfpgaContext&
+ * 3. Please keep the definition of OpenfpgaContext short
+ *    Do put ONLY well-modularized data structure under this root.
+ *******************************************************************/
+class OpenfpgaContext {
+  private:
+    /* Data structure to store information from read_openfpga_arch library */
+    openfpga::Arch arch_;
+};
+
+#endif
diff --git a/openfpga/src/base/openfpga_title.cpp b/openfpga/src/base/openfpga_title.cpp
new file mode 100644
index 000000000..4a33bb72e
--- /dev/null
+++ b/openfpga/src/base/openfpga_title.cpp
@@ -0,0 +1,43 @@
+/********************************************************************
+ * This file includes the functions to create the title page
+ * which introduces generality of OpenFPGA framework
+ *******************************************************************/
+#include "openfpga_title.h"
+
+/********************************************************************
+ * Generate a string of openfpga title introduction
+ * This is mainly used when launching OpenFPGA shell 
+ *******************************************************************/
+const char* create_openfpga_title() {
+  std::string title;
+
+  title += std::string("\n");
+  title += std::string("               OpenFPGA: An Open-source FPGA IP Generator\n");
+  title += std::string("\n");
+  title += std::string("Contributors: Xifan Tang\tAurelien Alacchi\tBaudouin Chauviere\n");
+  title += std::string("\n");
+  title += std::string("The MIT License\n");
+  title += std::string("\n");
+  title += std::string("Copyright (c) 2018 LNIS - The University of Utah\n");
+  title += std::string("\n");
+  title += std::string("Permission is hereby granted, free of charge, to any person obtaining a copy\n");
+  title += std::string("of this software and associated documentation files (the \"Software\"), to deal\n");
+  title += std::string("in the Software without restriction, including without limitation the rights\n");
+  title += std::string("to use, copy, modify, merge, publish, distribute, sublicense, and/or sell\n");
+  title += std::string("copies of the Software, and to permit persons to whom the Software is\n");
+  title += std::string("furnished to do so, subject to the following conditions:\n");
+  title += std::string("\n");
+  title += std::string("The above copyright notice and this permission notice shall be included in\n");
+  title += std::string("all copies or substantial portions of the Software.\n");
+  title += std::string("\n");
+  title += std::string("THE SOFTWARE IS PROVIDED \"AS IS\", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR\n");
+  title += std::string("IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,\n");
+  title += std::string("FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE\n");
+  title += std::string("AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER\n");
+  title += std::string("LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,\n");
+  title += std::string("OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN\n");
+  title += std::string("THE SOFTWARE.\n");
+  title += std::string("\n");
+
+  return title.c_str();
+}
diff --git a/openfpga/src/base/openfpga_title.h b/openfpga/src/base/openfpga_title.h
new file mode 100644
index 000000000..b4826964a
--- /dev/null
+++ b/openfpga/src/base/openfpga_title.h
@@ -0,0 +1,14 @@
+#ifndef OPENFPGA_TITLE_H
+#define OPENFPGA_TITLE_H
+
+/********************************************************************
+ * Include header files that are required by function declaration
+ *******************************************************************/
+#include <string>
+
+/********************************************************************
+ * Function declaration
+ *******************************************************************/
+const char* create_openfpga_title();
+
+#endif
diff --git a/openfpga/src/main.cpp b/openfpga/src/main.cpp
index ec445f46e..d3698d18d 100644
--- a/openfpga/src/main.cpp
+++ b/openfpga/src/main.cpp
@@ -1,34 +1,27 @@
 /********************************************************************
  * Build the OpenFPGA shell interface 
  *******************************************************************/
+/* Header file from vtrutil library */
 #include "vtr_log.h"
+
+/* Header file from libopenfpgashell library */
 #include "command_parser.h"
 #include "command_echo.h"
 #include "shell.h"
 
+/* Header file from openfpga */
 #include "vpr_main.h"
 
+#include "openfpga_title.h"
+#include "openfpga_context.h"
+
 using namespace openfpga;
 
-class ShellContext {
-  public:
-    int a;
-};
-
-static
-void shell_execute_set(ShellContext& context, 
-                       const Command& cmd, const CommandContext& cmd_context) {
-  CommandOptionId opt_id = cmd.option("value");
-  /* Get the value of a in the command context */
-  context.a = std::atoi(cmd_context.option_value(cmd, opt_id).c_str());
-}
-
-static
-void shell_execute_print(ShellContext& context) {
-  VTR_LOG("a=%d\n", context.a);
-}
-
+/********************************************************************
+ * Main function to start OpenFPGA shell interface
+ *******************************************************************/
 int main(int argc, char** argv) {
+
   /* Create the command to launch shell in different modes */
   Command start_cmd("OpenFPGA");
   /* Add two options:
@@ -47,70 +40,23 @@ int main(int argc, char** argv) {
 
   /* Create a shell object
    * Add two commands, which are
-   * 1. help
-   * 2. exit
+   * 1. exit
+   * 2. help. This must the last to add
    */
-  Shell<ShellContext> shell("OpenFPGA");
-  std::string shell_title;
+  Shell<OpenfpgaContext> shell("OpenFPGA");
 
-  shell_title += std::string("\n");
-  shell_title += std::string("               OpenFPGA: An Open-source FPGA IP Generator\n");
-  shell_title += std::string("\n");
-  shell_title += std::string("Contributors: Xifan Tang\tAurelien Alacchi\tBaudouin Chauviere\n");
-  shell_title += std::string("\n");
-  shell_title += std::string("The MIT License\n");
-  shell_title += std::string("\n");
-  shell_title += std::string("Copyright (c) 2018 LNIS - The University of Utah\n");
-  shell_title += std::string("\n");
-  shell_title += std::string("Permission is hereby granted, free of charge, to any person obtaining a copy\n");
-  shell_title += std::string("of this software and associated documentation files (the \"Software\"), to deal\n");
-  shell_title += std::string("in the Software without restriction, including without limitation the rights\n");
-  shell_title += std::string("to use, copy, modify, merge, publish, distribute, sublicense, and/or sell\n");
-  shell_title += std::string("copies of the Software, and to permit persons to whom the Software is\n");
-  shell_title += std::string("furnished to do so, subject to the following conditions:\n");
-  shell_title += std::string("\n");
-  shell_title += std::string("The above copyright notice and this permission notice shall be included in\n");
-  shell_title += std::string("all copies or substantial portions of the Software.\n");
-  shell_title += std::string("\n");
-  shell_title += std::string("THE SOFTWARE IS PROVIDED \"AS IS\", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR\n");
-  shell_title += std::string("IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,\n");
-  shell_title += std::string("FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE\n");
-  shell_title += std::string("AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER\n");
-  shell_title += std::string("LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,\n");
-  shell_title += std::string("OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN\n");
-  shell_title += std::string("THE SOFTWARE.\n");
-
-  shell.add_title(shell_title.c_str());
+  shell.add_title(create_openfpga_title());
 
   /* Add a new class of commands */
-  ShellCommandClassId arith_cmd_class = shell.add_command_class("Arithmetic");
-
-  /* Create a command of 'set' with a required option 'value' with a value 
-   * This function sets a value to an internal variable of ShellContext 
-   */
-  Command shell_cmd_set("set");
-  CommandOptionId set_opt_value = shell_cmd_set.add_option("value", true, "value of variable");
-  shell_cmd_set.set_option_require_value(set_opt_value, OPT_STRING);
-  ShellCommandId shell_cmd_set_id = shell.add_command(shell_cmd_set, "Set a value to internal variable 'a'");
-  shell.set_command_class(shell_cmd_set_id, arith_cmd_class);
-  shell.set_command_execute_function(shell_cmd_set_id, shell_execute_set);
-
-  /* Create a command of 'print' 
-   * This function will print the value of an internal variable of ShellContext 
-   */
-  Command shell_cmd_print("print");
-  ShellCommandId shell_cmd_print_id = shell.add_command(shell_cmd_print, "Print the value of internal variable 'a'");
-  shell.set_command_class(shell_cmd_print_id, arith_cmd_class);
-  shell.set_command_execute_function(shell_cmd_print_id, shell_execute_print);
+  ShellCommandClassId arith_cmd_class = shell.add_command_class("VPR");
 
   /* Create a macro command of 'vpr' which will call the main engine of vpr 
    */
   Command shell_cmd_vpr("vpr");
-  ShellCommandId shell_cmd_vpr_id = shell.add_command(shell_cmd_vpr, "A macro function to print arguments");
+  ShellCommandId shell_cmd_vpr_id = shell.add_command(shell_cmd_vpr, "Start VPR core engine to pack, place and route a BLIF design on a FPGA architecture");
   shell.set_command_class(shell_cmd_vpr_id, arith_cmd_class);
   shell.set_command_execute_function(shell_cmd_vpr_id, vpr::vpr);
 
-
   /* Add a new class of commands */
   ShellCommandClassId basic_cmd_class = shell.add_command_class("Basic");
 
@@ -126,7 +72,7 @@ int main(int argc, char** argv) {
   shell.set_command_execute_function(shell_cmd_help_id, [shell](){shell.print_commands();});
 
   /* Create the data base for the shell */
-  ShellContext shell_context;
+  OpenfpgaContext openfpga_context;
 
   /* Parse the option, to avoid issues, we use the command name to replace the argv[0] */
   std::vector<std::string> cmd_opts; 
@@ -142,13 +88,13 @@ int main(int argc, char** argv) {
   } else {
     /* Parse succeed. Start a shell */ 
     if (true == start_cmd_context.option_enable(start_cmd, opt_interactive)) {
-      shell.run_interactive_mode(shell_context);
+      shell.run_interactive_mode(openfpga_context);
       return 0;
     } 
 
     if (true == start_cmd_context.option_enable(start_cmd, opt_script_mode)) {
       shell.run_script_mode(start_cmd_context.option_value(start_cmd, opt_script_mode).c_str(),
-                            shell_context);
+                            openfpga_context);
       return 0;
     }
     /* Reach here there is something wrong, show the help desk */
diff --git a/openfpga/src/vpr_cmd/vpr_main.cpp b/openfpga/src/vpr_cmd/vpr_main.cpp
index 08b8348c4..5b9db0455 100644
--- a/openfpga/src/vpr_cmd/vpr_main.cpp
+++ b/openfpga/src/vpr_cmd/vpr_main.cpp
@@ -19,6 +19,8 @@
 #include "vpr_signal_handler.h"
 #include "vpr_tatum_error.h"
 
+#include "vpr_main.h"
+
 #include "globals.h"
 
 namespace vpr {