Ubuntu
对应GNOME桌面：
Windows --------- Ubuntu
Internet Explorer（及其衍生版） --------- Firefox（及其衍生版）, Opera, Epiphany, Midori, W3M,
Microsoft Office --------- OpenOffice.org, 永中office(EIOoffice)，Google Docs, GOffice(中文不推荐）
QQ--------- Pidgin，EVA, LinuxQQ, LumaQQ
Winamp -------- Xmms, Audacious
Photoshop --------- Gimp(Cinepaint)+Inkscape 或 Pixel
AIM, ICQ, MSN, Yahoo!, Jabber, IRC instant messaging --------- Pidgin
Skype --------- Skype，openwengo，voipstunt，Ekiga
Word Pad (or notepad) --------- Gedit, nano, vim1, medit, leafpad, mousepad
Windows Media Player --------- Totem, Mplayer, Gxine，SMPlayer, VLC
iTunes --------- 播放音乐:
-----------------------Exaile
-----------------------------Rhythmbox
---------------------- iPod Syncing
--------------------------------Gtkpod
ID3 tag editor ----------------------- easytag
MIRC -------- Xchat
Premiere (Movie Editing) --------- kino, CINELERRA
Bittorado --------- Bittorado
Dreamweaver --------- KompoZer
CDex ---------- Sound Juicer
Nero -------- K3b, Brasero, Nero3 For Linux
Outlook Express --------- Evolution, Thunderbird, Opera
Partition Magic --------- Gparted
eMule ----------- aMule, mldonkey
DC++ -------------- Valknut
BT下载 ------------ Azureus, 奔流
普通下载--------------- D4X, wget, Multiget, Axel, Gwet, mldonkey
regedit -------------------- gconf-editor
Adobe Illustrator ------------ Inkscape
Remote Desktop Connection ------------ Terminal Server Client
Windows Explorer ------------- Nautilus, Thuar, Rox-filer, Pcman filer
Windows Picture and Fax Viewer ------------ Image Viewer (Eye of GNOME)
Paint ------------- Jdraw, GNUPaint
Kubuntu
KDE桌面:
Internet Explorer --------- Konqueror, Firefox, Opera
Microsoft Office --------- OpenOffice.org, Eioofice, Google Docs, KOffice(中文不推荐）
QQ--------EVA, QQ, Pidgin
Winamp -------- Amarok
Photoshop --------- Gimp+Inkscape
Aol Instant Messenger --------- Kopete
Word Pad (or notepad) --------- Kwrite
Windows Media Player --------- Kaffeine, Smplayer
iTunes --------- -播放音乐:
-----------------------------Amarok
-----------------------------Juk
----------------------iPod Syncing
--------------------------------Gtkpod
Premiere (Movie Editing) --------- kino
Bittorado --------- Bittorado
BT下载 ------------ Azureus, 奔流
普通下载--------------- D4X, wget, Multiget, Axel, Kwet
Dreamweaver --------- KompoZer
CDex ---------- Kaudiocreator
Nero -------- K3B
Outlook Express --------- KMail, Thunderbird, Opera
Partition Magic --------- Qparted
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如果还有上面没有提到或者更好的，欢迎在下面跟帖回复。。
感谢dennis175
提供：
QQ游戏可以用蓝迪游戏 来代替（虽然人和游戏不是太多）凑个数
PS：WINE也可以运行一部分
感谢freshfish
提供：
最近发现一个可以代替Protel的软件：KiCAD，搜索一下就可以了。是法国人做的，GPL发布，最棒的是可以生成三维图！缺点就是这类软件的通病了：库文件不够全。另外，文档做的不错，正在学习中。
感谢solotim
提供
我的推荐
Explorer ----------------------- Thunar(within XFCE)
IE ----------------------- SwiftFox(Firefox)
GoogleTalk ----------------------- Jabbin(VoIP supported)
MSN ----------------------- aMsn(VoIP/Video supported), www.meebo.com
(webmessenger: GT,MSN,Yahoo,ICQ etc. supported)
QQ ----------------------- www.imhaha.com
(webmessenger: QQ,MSN etc supported)
EMail Client ----------------------- Sylpheed, Claws-Mail(两个轻量级的邮件客户端，比Thunderbird来的快多了)
Notepad ----------------------- MousePad(既然有人提，还是列出来这个，其实偶尔还是有用的)
龙卷风收音机 ----------------------- Streamtuner (比ljf强大多了)
Ultraedit ----------------------- GEdit(这个还是要逊色些)
EBWin ----------------------- EBView(查日文字典的), Stardict
MS Office ----------------------- OpenOffice, EIOffice, GNumeric(表格)
TVKoo, PPLive ----------------------- Sopcast
acrobat reader ----------------------- Xpdf
acdsee ----------------------- GQview
FROM：http://forum.ubuntu.org.cn/viewtopic.php?t=20859