I opened all apps in ulility, app and dev apps all at once on my 400MHz firewire powerbook (400MHz, 256MB ram). The results of top is:
Processes: 85 total, 9 running, 76 sleeping... 243 threads 16:58:34
Load Avg: 12.91, 10.95, 10.59 CPU usage: 75.4% user, 24.6% sys, 0.0% idle
SharedLibs: num = 134, resident = 17.3M code, 816K data, 3.57M LinkEdit
MemRegions: num = 8364, resident = 99.7M + 10.4M private, 68.2M shared
PhysMem: 35.7M wired, 145M active, 70.5M inactive, 251M used, 5.10M free
VM: 4.61G + 60.5M 83455(83455) pageins, 93238(93238) pageouts
PID COMMAND %CPU TIME #TH #PRTS #MREGS RPRVT RSHRD RSIZE VSIZE
4017 top 0.0% 0:00.52 1 14 15 284K 264K 520K 1.45M
3876 DirectoryS 0.0% 0:00.18 3 35 39 320K 592K 896K 3.56M
3870 MallocDebu 0.0% 0:00.69 1 58 67 924K 3.97M 2.57M 57.7M
3869 PackageMak 0.0% 0:00.85 1 58 70 968K 4.68M 3.41M 58.7M
3868 MRJAppBuil 0.0% 0:26.56 15 211 226 13.6M 11.1M 21.6M 253M
3867 Interface 0.0% 0:02.61 1 63 110 2.49M 5.07M 5.93M 61.7M
3866 IconCompos 0.0% 0:01.17 1 58 73 1.08M 4.23M 3.09M 58.1M
3864 icns Brows 0.0% 0:00.44 1 52 56 516K 3.14M 1.47M 52.6M
3863 OpenGLInfo 0.0% 0:00.76 1 60 76 824K 4.69M 3.28M 58.6M
3862 tcsh 0.0% 0:00.27 1 24 15 440K 520K 908K 5.72M
3861 Quartz Deb 0.0% 0:00.88 1 58 72 1.41M 3.94M 2.89M 58.0M
3860 FileMerge 0.0% 0:00.84 1 61 72 948K 4.15M 2.80M 58.3M
3859 Sampler 0.0% 0:00.74 1 58 69 988K 3.85M 2.60M 57.8M
3858 PropertyLi 0.0% 0:00.76 1 58 69 864K 5.11M 3.73M 59.0M
3857 PEFViewer 0.0% 0:10.37 1 45 55 380K 3.18M 1.10M 52.6M
3856 Apple Help 0.0% 0:10.90 2 67 61 400K 3.25M 1.18M 53.9M
3855 Thread Vie 0.0% 0:00.69 1 55 64 844K 3.54M 2.06M 57.8M
3854 Pixie 0.0% 0:24.85 1 57 66 1.20M 3.48M 2.19M 57.2M
3853 JavaBrowse 0.0% 0:01.41 1 60 108 1.65M 5.28M 4.79M 60.0M
3852 IORegistry 0.0% 0:04.78 1 303 76 2.77M 4.61M 5.05M 60.1M
3851 ObjectAllo 0.0% 0:01.58 1 61 125 3.37M 5.99M 5.83M 78.1M
3849 DebugNubCo 0.0% 0:00.67 1 58 68 796K 3.63M 2.13M 57.5M
3847 tail 0.0% 0:00.21 1 12 13 24K 232K 204K 1.25M
3846 System Pre 0.0% 0:01.44 1 58 74 356K 4.58M 2.55M 59.6M
3845 TextEdit 0.0% 0:00.87 1 60 71 36K 4.39M 1.94M 58.4M
3844 QuickTime 0.0% 0:54.21 5 85 99 3.80M 5.65M 6.98M 64.6M
3843 GraphicCon 0.0% 0:05.26 1 46 85 140K 3.39M 960K 57.3M
3842 Carracho X 0.0% 0:11.77 4 106 108 836K 6.90M 4.75M 64.9M
3841 java 0.0% 1:52.42 17 231 250 14.5M 9.32M 20.7M 254M
3837 ColorSync 0.0% 0:15.61 2 77 98 936K 4.82M 3.43M 59.1M
3836 Directory 0.0% 0:01.24 1 75 75 220K 3.73M 1.78M 59.0M
3835 Terminal 0.0% 0:06.22 4 64 113 1.64M 6.61M 5.85M 63.0M
3834 Applet Lau 0.0% 0:14.05 13 198 212 8.31M 8.95M 13.6M 249M
3832 NetInfo Ma 0.0% 0:01.77 1 59 74 160K 4.62M 2.57M 58.8M
3831 Grab 0.0% 0:00.40 1 55 65 0K 3.30M 924K 53.4M
3830 Calibrator 0.0% 0:17.24 1 54 78 120K 3.32M 948K 55.2M
3829 CPU Monito 0.0% 0:14.11 1 60 78 1.17M 3.64M 2.33M 57.6M
3828 AirPort Ad 0.0% 0:01.56 3 82 83 68K 3.51M 1.20M 59.3M
3827 Installer 0.0% 0:01.29 1 62 114 352K 3.50M 1.77M 60.9M
3826 ProcessVie 0.0% 0:29.26 3 63 81 1.04M 4.52M 3.36M 60.0M
3825 DigitalCol 0.0% 0:18.60 1 66 84 1.24M 3.94M 2.50M 57.9M
3824 AirPort Se 0.0% 0:01.41 1 57 87 60K 3.58M 1.41M 60.5M
3823 Disk Utili 0.0% 0:01.85 1 107 112 908K 4.51M 3.19M 59.8M
3822 Keychain A 0.0% 0:14.23 1 54 73 308K 3.31M 1.27M 54.9M
3821 Apple Syst 0.0% 0:02.76 2 69 95 364K 5.46M 3.34M 66.7M
3820 StuffIt Ex 0.0% 0:04.42 1 46 65 68K 3.31M 828K 55.7M
3819 Network Ut 0.0% 1:04.31 1 59 75 820K 3.96M 2.47M 58.5M
3818 Print Cent 0.0% 1:41.88 2 77 72 588K 3.52M 1.54M 55.7M
3817 Key Caps 0.0% 0:00.82 1 54 90 268K 3.29M 1.09M 59.0M
3816 Console 0.0% 0:10.92 4 62 174 2.61M 3.67M 2.80M 60.6M
3815 Disk Copy 0.0% 0:00.78 1 60 69 0K 3.45M 1012K 57.7M
3814 ICQ 0.0% 2:23.10 8 122 132 3.25M 7.13M 7.32M 101M
3795 Internet E 0.0% 14:37.76 19 230 377 2.74M 12.0M 9.39M 280M
3794 Mail 0.0% 0:19.23 6 124 119 2.95M 6.57M 6.91M 65.3M
3596 iTunes 0.0% 41:34.95 9 134 188 2.57M 4.57M 4.06M 68.6M
3062 Project Bu 0.0% 20:14.73 6 143 250 3.98M 6.98M 7.66M 82.7M
1676 hdid 0.0% 0:00.17 1 11 18 56K 248K 124K 1.70M
1578 Finder 0.0% 2:31.02 2 85 1010 4.97M 6.39M 6.46M 94.2M
286 SystemUISe 0.0% 8:44.99 4 131 179 1.12M 4.30M 1.81M 61.5M
285 Dock 0.0% 3:18.71 3 191 153 1.82M 5.86M 3.00M 58.6M
259 pbs 0.0% 0:04.75 1 60 26 444K 396K 772K 18.4M
256 loginwindo 0.0% 13:13.86 8 209 180 1.51M 3.98M 2.13M 66.7M
252 cron 0.0% 0:00.78 1 9 15 24K 240K 92K 1.52M
244 SecuritySe 0.0% 0:02.27 1 45 19 80K 340K 152K 2.34M
233 automount 0.0% 0:00.06 2 11 18 0K 220K 36K 2.14M
230 nfsiod 0.0% 0:00.00 1 9 12 0K 220K 36K 1.25M
228 nfsiod 0.0% 0:00.00 1 9 12 0K 220K 36K 1.25M
227 nfsiod 0.0% 0:00.00 1 9 12 0K 220K 36K 1.25M
215 inetd 0.0% 0:00.00 1 9 13 0K 220K 36K 1.26M
208 coreservic 0.0% 0:25.61 4 108 38 360K 340K 508K 3.70M
202 ntpd 0.0% 0:25.63 1 9 15 28K 248K 100K 1.49M