# Differences from 2.3

Overview of difference between Teraterm 2.3 (original version) by Takashi Teranishi and Tera Term 4 and Tera Term 5.

## Feature Differences

Content | Tera Term Pro 2.3 | Tera Term 4 | Tera Term 5
--- | --- | --- | ---
Source code | Opened | Opened | Opened
License | Proprietary*1 | Modified BSD license*2 | Modified BSD license
Development tool | Visual C++ 5.0 / Watcom C/C++ 11.0 | Visual Studio 2005 | Visual Studio 2019
Icon | *3 | *3 | *3
Maximum COM port | 16 | 4096 | 4096
Serial speed | from 110 to 115200 | from 110 to 921600, and editable | from 110 to 921600, and editable
Japanese character code | EUC-JP/Shift_JIS/JIS | EUC-JP/Shift_JIS/JIS/UTF-8/UTF-8 MAC | EUC-JP/Shift_JIS/JIS/UTF-8
Unicode support | Not supported | Support single language*4 | Support multi language
IPv6 support | No | Yes | Yes
i18n support | No | Yes*5 | Yes
Linked library |  | Oniguruma SFMT | Oniguruma SFMT *6
TTSSH icon |  | *3 | *3
supported SSH version | SSH 1.5 | SSH 1.5 and 2 | SSH 1.5 and 2
supported SSH feature | shell, port-forwarding, X11 forwarding | shell, port-forwarding, X11 forwarding, SCP | shell, port-forwarding, X11 forwarding, SCP
Pageant*7 collaboration | No | Yes | Yes
Linked library | SSLeay zlib | OpenSSL used as the encryption library, but not used as TLS zlib PuTTY used for cooperation with Pageant, but not used for communication and terminal emulation argon2 | LibreSSL used as the encryption library, but not used as TLS zlib PuTTY used for cooperation with Pageant, but not used for communication and terminal emulation argon2 *6
Proxy | No | Yes*8 (HTTP, TELNET, SOCKS4, SOCKS5) | Yes (HTTP, TELNET, SOCKS4, SOCKS5)

- [*1] Without written permission by the author (Takashi Teranishi), you may not distribute modified versions of this package, and may not distribute this package for profit.
- [*2] Tera Term is distributed under Modified BSD License.
- [*3] Icon designer is Tatsuhiko Sakamoto.
- [*4] Tera Term can not simultaneously display multi languages because it has not completely implemented as Unicode API. Now Tera Term mutually converts between Unicode(UCS-2) and MBCS. Also, Chinese version Windows can display Chinese characters when you configure the locale for Unicode.
- [*5] You can switch the message language by using the language file(lang\*.lng). You need to re-startup Tera Term to active new message language.
- [*6] Detail of libraries
- [*7] An SSH authentication agent for PuTTY and WinSCP.
- [*8] Using TTProxy.