Inclusion Criteria:

• Histologically confirmed sarcoma that is recurrent or refractory to conventional treatment
• Measurable disease by RECIST criteria
• ECOG performance status < 2 (or Lansky/Karnofsky > 60% for children)
• Life expectancy greater than 3 months
• Adequate organ function
• absolute neutrophil count at least 1,500
• platelets at least 100,000
• bilirubin less than 1.5 x upper limit of normal
• AST and ALT less than 2.5 x upper limit of normal
• creatinine less than 1.5 x upper limit of normal OR creatinine clearance at least 60 ml/min/1.73 m2
• fasting serum cholesterol less than 350
• fasting serum triglycerides less than 400
• PT or INR less than 1.3 x upper limit of normal
• normal urinalysis
• Ability to understand and sign the informed consent document

Exclusion Criteria:

• Prior chemotherapy or radiotherapy within 3 weeks of entering the study (6 weeks for nitrosoureas or mitomycin C)
• Prior treatment with a tyrosine kinase inhibitor within 10 days of entering the study
• History of pulmonary hypertension or pneumonitis
• Patients may not be receiving other investigational agents
• Prior therapy with rapamycin, rapamycin analogues, or tacrolimus
• Uncontrolled brain metastases
• History of grade 3 or 4 hypersensitivity to macrolide antibiotics
• Concurrent treatment with immunosuppressive agents other than a stable (for more than 2 weeks) dose of corticosteroids
• Uncontrolled intercurrent illness
• Pregnancy or breast feeding
• HIV-positive patients on combination antiretroviral therapy
• Grade 3 or 4 proteinuria