官方下载, 用开发者账户登录，建议用Safari浏览器下载.
官方下载地址:
https://developer.apple.com/xcode/downloads/
Xcode 6
6.4: http://developer.apple.com/devcenter/download.action?path=/Developer_Tools/Xcode_6.4/Xcode_6.4.dmg
6.3.2: http://developer.apple.com/devcenter/download.action?path=/Developer_Tools/Xcode_6.3.2/Xcode_6.3.2.dmg
6.2: http://developer.apple.com/devcenter/download.action?path=/Developer_Tools/Xcode_6.2/Xcode_6.2.dmg
6.1.1: https://developer.apple.com/devcenter/download.action?path=/Developer_Tools/xcode_6.1.1/xcode_6.1.1.dmg
6.0.1: https://developer.apple.com/devcenter/download.action?path=/Developer_Tools/xcode_6.0.1/xcode_6.0.1.dmg
Xcode 5
5.1.1: https://developer.apple.com/devcenter/download.action?path=/Developer_Tools/xcode_5.1.1/xcode_5.1.1.dmg
5.0.2: https://developer.apple.com/devcenter/download.action?path=/Developer_Tools/xcode_5.0.2/xcode_5.0.2.dmg
Xcode 4
4.6.3: https://developer.apple.com/devcenter/download.action?path=/Developer_Tools/xcode_4.6.3/xcode4630916281a.dmg
4.5.2: https://developer.apple.com/devcenter/download.action?path=/Developer_Tools/xcode_4.5.2/xcode4520418508a.dmg
4.4.1: https://developer.apple.com/devcenter/download.action?path=/Developer_Tools/xcode_4.4.1/xcode_4.4.1_6938145.dmg
4.3.2: https://developer.apple.com/devcenter/download.action?path=/Developer_Tools/xcode_4.3.2/xcode_432_lion.dmg
4.2: http://developer.apple.com/devcenter/download.action?path=/Developer_Tools/xcode_4.2_for_lion_21264/installxcode_42_lion.dmg
4.1: http://developer.apple.com/devcenter/download.action?path=/Developer_Tools/xcode_4.1_for_lion_21263/installxcode_41_lion.dmg
4.0.2: http://developer.apple.com/devcenter/download.action?path=/Developer_Tools/xcode_4.0.2_and_ios_sdk_4.3/xcode_4.0.2_and_ios_sdk_4.3.dmg
Xcode 3以下:
3.2.6: http://developer.apple.com/devcenter/download.action?path=/Developer_Tools/xcode_3.2.6_and_ios_sdk_4.3__final/xcode_3.2.6_and_ios_sdk_4.3.dmg
3.1.4: http://developer.apple.com/devcenter/download.action?path=/Developer_Tools/xcode_3.1.4_developer_tools/xcode314_2809_developerdvd.dmg
3.0: http://developer.apple.com/devcenter/download.action?path=/Developer_Tools/xcode_3.0/xcode_3.0.dmg
2.5: http://developer.apple.com/devcenter/download.action?path=/Developer_Tools/xcode_2.5_developer_tools/xcode25_8m2558_developerdvd.dmg
2.4.1: http://developer.apple.com/devcenter/download.action?path=/Developer_Tools/xcode_2.4.1/xcode_2.4.1_8m1910_6936315.dmg
2.3: http://developer.apple.com/devcenter/download.action?path=/Developer_Tools/xcode_2.3/xcode_2.3_8m1780_oz693620813.dmg
2.2.1: http://developer.apple.com/devcenter/download.action?path=/Developer_Tools/xcode_tools_2.2.1/xcode_2.2.1_8g1165_018213632.dmg
1.5: http://developer.apple.com/devcenter/download.action?path=/Developer_Tools/xcode_v1.5/xcode_tools_1.5_cd.dmg.bin
1.0: http://developer.apple.com/devcenter/download.action?path=/Mac_OS_X/Mac_OS_X_10.3_Build_7B85/7B85_Xcode_CD.dmg