# Differences between 2.3, 4 and 5

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 2022
Icon | *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*6 |  | Oniguruma used as the regular expressions library SFMT used as the random number generator | Oniguruma used as the regular expressions library SFMT used as the random number generator
TTSSH icon |  |  |
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*6 | SSLeay used as the cryptographic library (libeay32.lib) not used as SSL library (not ssleay32.lib) zlib used as the compression library | OpenSSL used as the cryptographic library not used as TLS library zlib used as the compression library argon2 used for decrypt PuTTY private key file PuTTY used for display tooltip used for cooperation with Pageant not used for communication and terminal emulation | LibreSSL used as the cryptographic library, but not used as TLS zlib used as the compression library argon2 used for decrypt PuTTY private key file PuTTY used for display tooltip used for cooperation with Pageant not used for communication and terminal emulation RLogin used for cooperation with Pageant
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.