*** VDT Version 2.8.x (Release: XXX)

1. Update alias-declaration processing
   For object-alias without subtype-indication.

2. Update component-configuration processing
   For incremental binding without entity-aspect,
   Which is identified without `MaskNoIncrementalBinding'.

3. Support of memory-release-functions,
   Design::clean() for design unit. 
   Lib::close() for design library.


*** VDT Version 2.8.3 (Release: October 10, 2001)

1. Report-statement is distinguished 
   From assertion-statement
   By no assert-condition.

2. Added field `mask' to Basic object,
   Use set/get_mask() function
   For marking/retrieving object-properties 
   With proper mask-constant.

3. Restrict field `flag' for application-specific,
   Use set/get_flag() function
   For setting/retrieving the field.

4. Optimize performance and memory-usage
   By rewriting of LinearMap.h


*** VDT Version 2.8.2 (Release: September 7, 2001)

1. Change gen_XXX() functions for Basic object
   From: gid gen_XXX() const
   To: const gid& gen_XXX() const

2. Change gen_values() function for Basic object
   From: gval gen_values() const
   To: const gval& gen_values() const

3. Change search() function for Basic object
   From: gid search(...)
   To: const gid& search(...)

4. Used field `flag' of Basic object
   For marking various object-properties.
   Added set/get_mask() function for Basic object
   For marking/retrieving object-properties.

5. Used T_subtype for representing subtype-indication
   Forbidden using fields `res_func', `type', `ranges'
   Of other objects except T_subtype.


*** VDT Version 2.8.1 (Release: July 3, 2001)

1. Change directory-structure for design-library
   From: primary__secondary
   To: primary/secondary

2. Change filename for intermediate-form file
   From suffix of "XXX.if"
   To suffix of "XXX__[e|a|c|p|b].vif"

4. Deprecated isRight() member-functions
   Recommended isRight() friend-functions.

3. Improve locally-static-semantic checking,
   Especially with case-choices and aggregate.


*** VDT Version 2.8 (Release: August 30, 1999)

1. New support
   Of comment-processing.

2. Added field `comments' 
   To SP_procedure and SP_function.

3. Replaced field `comment' 
   To `comments'.


*** VDT Version 2.7 (Release: December 30, 1997)

1. New support 
   Of VHDL'93 specification.

2. Put ST_generate into Symbols group,
   With many new fields for declarations.

3. Added field `name' for statement-label 
   To almost statements,
   Except ST_cond_wave, ST_sel_wave, ST_waveform, ST_if_alt, ST_case_alt

4. Added field `time_expr' 
   For delay-mechanism,
   To ST_cond_sig_assign, ST_sel_sig_assign, ST_sig_assign.

5. Support waveform UNAFFECTED,
   Represented by ST_waveform 
   (_value_expr = NULL, _time_expr = NULL).

6. Support POSTPONED process,
   Represented by setting field `flag' 
   To non-zero.

7. Support IMPURE function,
   Represented by setting field `flag' 
   To non-zero.


*** VDT Version 2.6 (Release: December 1, 1996)

1. Renamed field `raw_value' of O_literal
   To `string'.

2. Renamed field `bit_string_value' of L_bit_string
   To `string_value'.

3. Renamed field `int_value' of L_integer
   To `abstract_value'.

4. Renamed field `float' of L_float
   To `abstract_value'.

5. Renamed field `initial_expr' of O_constant,
   O_signal, O_variable, and O_file to `expression'.

6. Added O_comment as one of Basic object.


*** VDT Version 2.5 (Release: January 31, 1996)

1. Renamed source files,
   From: interface.h interface.cc
   To basicMan.h basicMan.cpp

2. Renamed source files,
   From: objman.h objman.cc
   To: basicSup.h basicSup.cpp

3. Renamed source files,
   From: desman.h desman.cc
   To: designMan.h designMan.cpp

4. Renamed source files,
   From: libman.h libman.cc
   To: libraryMan.h libraryMan.cpp

5. Renamed Design object for package-body,
   From (package-identifier + "__" )
   To (package-identifier + "__" + package-identifier)

6. Removed O_ext_ref
   Which was used for external-reference.

7. Removed L_character,
   Which was used for character-literal.

8. Removed field `symbols' 
   From O_context.

9. Removed routine `search' 
   From O_library.

10. Added field `ext_ref' to O_use
    With removing fields `library/design_unit/suffix'.

11. Added routine `search' 
    To O_use.

12. Removed field `ext_refs' from O_context, O_use,
    O_arch_body, O_pack_body, and O_configuration.

13. Added field `function' to arithmetical-operator,
    Which points to O_subprogram 
    After overloading-resolution.

14. Create implicitly-declared-subprograms
    For file-type and access-type 
    While analyzing.

15. Support extended-graphic-character 
    For Hangul comment.

16. Provided
    VHDL static-semantic-checker.


*** VDT Version 2.0 (Release: December 30, 1994)

1. Defined Basic object in files,
   interface.h interface.cc
   objman.h objman.cc

2. Defined Design object in files,
   desman.h desman.cc

3. Defined Lib object in files,
   libman.h libman.cc

4. Provided VDT utilities,
   VHDL-Code analyzer
   VHDL-Code generator
   Design-Library browser
   VIF (VHDL Intermediate Form) dumper.