Myelosuppressive chemotherapy: must not have received within 2 weeks of entry onto this study Cytotoxic chemotherapy or other anti-cancer agents known to be myelosuppressive; the duration of this interval must be discussed with the study chair and the study-assigned research coordinator prior to enrollment\r\n* >= 21 days after the last dose of cytotoxic or myelosuppressive chemotherapy (42 days if prior nitrosourea) At least 21 days after the last dose of myelosuppressive chemotherapy (42 days if prior nitrosourea) Patients with solid tumors must not have received myelosuppressive chemotherapy within 3 weeks of enrollment onto this study (6 weeks if prior nitrosourea) Patients must have received their last dose of known myelosuppressive anticancer therapy at least 21 days prior to enrollment or at least 42 days if nitrosourea Patients must not have received myelosuppressive therapy within 2 weeks of enrollment onto this study (6 weeks if prior nitrosourea) Myelosuppressive chemotherapy: must not have received within 4 weeks of registration onto this study (6 weeks if prior nitrosourea) Patients must have received their last dose of known myelosuppressive anticancer chemotherapy at least 21 days prior to study registration or at least six weeks if nitrosourea; at least two weeks must have lapsed if patients received lower dose oral etoposide (50 mg/2) without experiencing evidence of myelosuppression (i.e. neutropenia or requiring transfusion with blood products) Myelosuppressive chemotherapy: at least 21 days after the last dose of myelosuppressive chemotherapy (42 days if prior nitrosourea) Myelosuppressive chemotherapy: Must not have received within 2 weeks of entry onto this study (4 weeks if prior nitrosourea) Myelosuppressive chemotherapy: Must not have received within 4 weeks of enrollment onto this study (6 weeks if prior nitrosourea) Patients must not have received myelosuppressive chemotherapy within 3 weeks of enrollment onto this study (6 weeks if prior nitrosourea). Myelosuppressive chemotherapy: patients must have received their last dose of known myelosuppressive anticancer chemotherapy at least three weeks prior to study registration or at least six weeks if nitrosourea Myelosuppressive chemotherapy: Must not have received within 2 weeks of enrollment onto this study (6 weeks if prior nitrosourea). Patients must have received their last dose of known myelosuppressive anticancer therapy at least three (3) weeks prior to study enrollment or at least six (6) weeks if prior nitrosourea INCLUSION CRITERIA FOR STRATUM C: Patients must have received their last dose of known myelosuppressive anticancer therapy at least three (3) weeks prior to study enrollment or at least six (6) weeks if prior nitrosourea Chemotherapy: patients must have received their last dose of known myelosuppressive anticancer chemotherapy at least three (3) weeks prior to study enrollment in the study or at least six (6) weeks for those receiving nitrosourea Participant has received no prior radiotherapy or chemotherapy for RMS (excluding steroids); at least 6 weeks must have passed since last dose of myelosuppressive chemotherapy or radiation therapy for conditions other than RMS; patients must have recovered from acute toxicity of any prior myelosuppressive chemotherapy or radiation therapy; prior biopsy, surgical resection and lymph node sampling is allowed Myelosuppressive chemotherapy Patients must have received their last dose of known myelosuppressive anticancer chemotherapy at least three weeks prior to study registration or at least six weeks if nitrosourea Myelosuppressive chemotherapy, immunotherapy, or any investigational agent: ? 21 days (? 42 days if a nitrosourea) prior to screening. Must not have received myelosuppressive chemotherapy within 21 days prior to study drug administration (42 days if prior nitrosourea). Myelosuppressive chemotherapy: must not have received within 4 weeks of entry onto this study Patients must not have received myelosuppressive chemotherapy within 2 weeks of enrollment onto this study (6 weeks if prior nitrosourea) Patients must not have received myelosuppressive therapy within 3 weeks of enrollment onto this study (6 weeks if prior nitrosourea) Chemotherapy: \r\n* Must not have received myelosuppressive chemotherapy within 3 weeks of the study entry (6 weeks if prior nitrosourea); prior treatment with either dasatinib or temsirolimus but not both is allowed; at least 3 weeks must have elapsed from the last dose Patients must have recovered from the toxic effects of prior therapy to grade 1 or better; patients must be at least 3 weeks form the last dose of standard cytotoxic chemotherapy or myelosuppressive biological therapy and at least 1 week from the last dose of non-myelosuppressive biologic therapy At least 21 days after the last dose of myelosuppressive chemotherapy (42 days if prior nitrosourea). Myelosuppressive chemotherapy: must not have received within 3 weeks of enrollment onto this study (6 weeks if prior nitrosourea) Must not have received myelosuppressive chemotherapy and/or biologics within 3 weeks of entry onto this study (4 weeks if prior nitrosourea) Myelosuppressive chemotherapy: Must not have received within 2 weeks of enrollment onto this study (6 weeks if prior nitrosourea). Patient must have received last dose of known myelosuppressive chemotherapy > 21 days prior to enrollment; > 42 days if nitrosurea Evidence of recovery from any prior chemotherapy; no myelosuppressive anticancer chemotherapy or biological therapy within 3 weeks (6 weeks if a nitrosourea or mitomycin C agent) prior to registration Myelosuppressive chemotherapy: must not have received within 28 days of entry onto this study (42 days if prior nitrosourea drug) accompanied by hematopoietic recovery or 14 days of stopping non-myelosuppressive therapy as long as hematopoietic requirements are met Cytotoxic chemotherapy or other chemotherapy known to be myelosuppressive: ?21 days after the last dose of cytotoxic or myelosuppressive chemotherapy (42 days if prior nitrosourea). Myelosuppressive chemotherapy: must not have received myelosuppressive chemotherapy within 3 weeks of entry onto this study (excluding hydroxyurea)\r\n* Cytoreduction with hydroxyurea can be initiated and continued for up to 24 hours prior to the start of CPX-351 Myelosuppressive chemotherapy: at least 21 days after the last dose of myelosuppressive chemotherapy (42 days if prior nitrosourea) MDS: No previous myelosuppressive therapy; for the purpose of this protocol myelosuppressive chemotherapy will be defined as chemotherapy given with the intent of inducing a complete remission (e.g., standard 7+3, high dose intermittent ARA-C [HIDAC], or Mylotarg) MPD: No previous myelosuppressive therapy; for the purpose of this protocol myelosuppressive chemotherapy will be defined as chemotherapy given with the intent of inducing a complete remission (e.g., standard 7+3, HIDAC, or Mylotarg) Atypical CML: No previous myelosuppressive therapy; for the purpose of this protocol myelosuppressive chemotherapy will be defined as chemotherapy given with the intent of inducing a complete remission (e.g., standard 7+3, HIDAC, or Mylotarg) Patients must have received their last dose of known myelosuppressive anticancer therapy greater than 28 days prior to study enrollment or > 42 days if nitrosourea Myelosuppressive chemotherapy: must not have received within 4 weeks of entry onto this study Myelosuppressive chemotherapy: Must not have received within 3 weeks (6 weeks if prior nitrosourea) Myelosuppressive chemotherapy:\r\n* Subjects must have received their last dose of known myelosuppressive anticancer chemotherapy at least three (3) weeks prior to study registration or at least six (6) weeks if nitrosourea Cytotoxic chemotherapy or other chemotherapy known to be myelosuppressive: ?21 days after the last dose of cytotoxic or myelosuppressive chemotherapy (42 days if prior nitrosourea) Myelosuppressive chemotherapy: interval >= 6 weeks and >= 4 weeks from last dose of nitrosourea and other chemotherapy drugs before study enrollment, respectively; however, interval must be >= 1 week from last dose of oral etoposide and other drugs administered at low doses (metronomic regimen) before study enrollment Patients must have received their last dose of known myelosuppressive anticancer chemotherapy at least three (3) weeks prior to study registration or at least six (6) weeks if nitrosourea Myelosuppressive chemotherapy: patients must not have received myelosuppressive chemotherapy within 3 weeks of enrollment (6 weeks if prior nitrosourea) RECURRENT/ PROGRESSIVE DIPG (STRATUM 1): Patients must have received their last dose of known myelosuppressive anticancer therapy or immunotherapy at least 21 days prior to enrollment (42 days if prior nitrosourea) Patients must not have received myelosuppressive therapy within 2 weeks of enrollment onto this study (6 weeks if prior nitrosourea) Myelosuppressive chemotherapy: Last dose was given at least 14 days before the start date for protocol therapy. Chemotherapy: Must not have received myelosuppressive chemotherapy within 3 weeks prior to study entry (6 weeks if prior nitrosourea) Planned non-myelosuppressive chemotherapy regimen Patient must not have had myelosuppressive chemotherapy =< 3 weeks prior to entry onto this study (or 6 weeks if prior nitrosourea) Chemotherapy: ?14 days from any myelosuppressive chemotherapy and abs neutrophil ct ?1000/mm3 , 42 days if prior nitrosurea